Directory of Researchers
| IIZUKA Atsushi |  |
| Resaarch Center for Urban Safety and Security | |
| Professor | |
| Civil Engineering / Architecutre and planning / Building Engineering |
Researcher Profile and Settings
Affiliation
＜Faculty / Graduate School / Others＞
Resaarch Center for Urban Safety and Security＜Related Faculty / Graduate School / Others＞
Faculty of Engineering / Department of Civil Engineering, Graduate School of Engineering / Department of Civil Engineering, Center for Computational Social Science (CCSS)
Teaching
- Office for the Promotion of International Exchange, 2021, The Great Hanshin-Awaji Earthquake A
- Office for the Promotion of International Exchange, 2021, The Great Hanshin-Awaji Earthquake B
- Graduate School of Engineering / Department of Architecture, 2021, Computational Mechanics I
- Graduate School of Engineering / Department of Architecture, 2021, Computational Mechanics Ⅱ
- Graduate School of Engineering / Department of Architecture, 2021, Computational Mechanics Ⅲ
- Graduate School of Engineering / Department of Civil Engineering, 2021, Computational Geotechnical Engineering
- Faculty of Engineering / Department of Civil Engineering, 2021, Foundation Engineering
- Faculty of Engineering / Department of Civil Engineering, 2021, International Relations in Civil Engineering
- Faculty of Engineering / Department of Civil Engineering, 2021, International Relations in Civil Engineering
- Faculty of Engineering / Department of Civil Engineering, 2021, Introduction to Continuum Mechanics
- Faculty of Engineering, 2021, Advanced Liberal Arts Seminar in Faculty of Engineering (Civil Engineering)
Research at Kobe
Research Activities
Research Interests
Research Areas
- Social infrastructure (civil Engineering, architecture, disaster prevention) / Geotechnical engineering
Committee Memberships
- Jun. 2015 - May 2017, 土木学会, 調査研究部門 地盤工学委員会 小委員長
- Apr. 2012, 地盤工学会, 第１５回国際地盤工学会アジア地域会議実行委員会・委員
- Oct. 2011, 地盤工学会, 東日本大震災対応調査研究委員会【地盤環境研究委員会】委員
Awards
Jun. 2020 Institution of Civil Engineers, ICE Publishing Awards 2020, Telford Premium, Extension of unsaturated soil mechanics and its applications
Aug. 2014 独立行政法人 日本学術振興会, 平成25年度日本学術振興会・特別研究員等審査会専門委員 （書面担当）表彰
Others
May 2008 地盤工学会, 平成19年度 地盤工学会技術開発賞, 土／水連成弾（粘）塑性有限要素・飽和地盤静的解析パッケージDACSARの開発と実用化
May 2008 地盤工学会, 平成19年度 地盤工学会 功労章
Jan. 2008 土木学会関西支部, 支部活動功労賞（土木学会関西支部創立80周年記念）
Jun. 2007 地盤工学会, Award by Japanese Society of Geotechnical Enginnering, 2007, 地盤工学会技術者交流特別セッションの企画と運営
Oct. 2006 神戸大学工学部, Excellent teacher, Faculty of Engineering, Kobe University, 2006, 平成17年度後期学部授業「連続体力学」
May 1990 土質工学会(地盤工学会), Award by Japanese Society of Geotechnical Enginnering, 1990, General Theory of shear bands formation by a non-coaxial Cam-clay model
Published Papers
- International Journal of Geomate, 01 Jun. 2021, International Journal of GEOMATE, 20 (82), 161 - 169, English
[Refereed]
Scientific journal
- Mar. 2021, 神戸大学都市安全研究センター研究報告, (25), 181 - 190, Japanese自然災害への対峙的な防災・減災からの脱却
Research institution
- Mar. 2021, 神戸大学都市安全研究センター研究報告, (25), 62 - 74, Japanese盛立ておよび降雨過程における盛土の圧縮挙動の有限要素解析
Research institution
- Mar. 2021, 神戸大学都市安全研究センター研究報告, (25), 51 - 61, Japanese粘土鉱物の変質に起因する間隙水圧の上昇とスロースリップ
Research institution
- Mar. 2021, 神戸大学都市安全研究センター研究報告, (25), 42 - 50, Japanese土/水/空気連成動的解析を用いたアーチ効果の液状化への影響の解析的検討
Research institution
- Mar. 2021, 神戸大学都市安全研究センター研究報告, (25), 33 - 41, Japanese機械学習による過圧密比の深度分布推定
Research institution
- Mar. 2021, 神戸大学都市安全研究センター研究報告, (25), 22 - 32, Japanese粘土緩衝材を対象とした熱／水／空気／応力連成解析手法の開発
Research institution
- Elsevier BV, Oct. 2020, Soils and Foundations, 60 (5), 1287 - 1298, English
[Refereed]
Scientific journal
- International Journal of Geomate, 01 Sep. 2020, International Journal of GEOMATE, 19 (73), 148 - 155, English
[Refereed]
Scientific journal
- Mar. 2020, 神戸大学都市安全研究センター研究報告, (24), 66 - 76, Japaneseベントナイトの膨潤圧試験における壁面摩擦の影響に関する数値解析的検討
Research institution
- Mar. 2020, 神戸大学都市安全研究センター研究報告, (24), 53 - 65, Japanese最適化手法を用いた土/水連成問題に対する分離型解法の収束性に関する研究
Research institution
- Mar. 2020, 神戸大学都市安全研究センター研究報告, (24), 34 - 43, Japanese層間水の脱水による土粒子密度変化を考慮した連続条件式
Research institution
- Mar. 2020, 神戸大学都市安全研究センター研究報告, (24), 44 - 52, Japanese室内試験に基づく繰り返し挙動を表現できる構成モデルのパラメータ同定方法
Research institution
- Mar. 2020, 神戸大学都市安全研究センター研究報告, (24), 25 - 33, Japaneseベイズ推定を用いた被害規模予測モデルの改善
Research institution
- Mar. 2020, 神戸大学都市安全研究センター研究報告, (24), 18 - 24, Japaneseせん断強度に基づく飽和度変化に起因する硬化特性の定量的評価
Research institution
- Elsevier BV, Feb. 2020, Soils and Foundations, 60 (1), 179 - 197, English
[Refereed]
Scientific journal
Although the soil, water and air coupling theory has been deductively derived from the three-phase mixture theory, assumptions and interpretations inherent in soil mechanics are also conveniently introduced in this theory. Mechanical properties of unsaturated soils are phenomenologically integrated into the constitutive equation for a deformation problem, with effective stress expressed as a combination of partial stresses acting on each phase of the mixture. The governing equations of two seepage problems describing the movements of pore water and pore air are formulated by a priori introduction of Darcy's law. Consequently, the coupling theory consists of a deformation problem and two seepage problems, in which the soil-water retention characteristics play the role of a mediator connecting these problems. If the theoretical structure is clarified in this way, an extension of this theory is easily made. In this paper, the extension of the theory to each of four examples and their performance is demonstrated. The features of settlement caused by absorption of soil water due to vegetation; dissolution, advection and diffusion of substances in groundwater; desaturation and state change due to vaporisation of dissolved gas from pore water; and the liquefaction potential of unsaturated soil are presented.
ICE Publishing, 01 Sep. 2019, Geotechnical Research, 6 (3), 156 - 176, English[Refereed]
Scientific journal
In the wide area of the eastern part of Tokyo, the ground level is less than mean sea level. This area is more vulnerable to disasters than other areas. If large flood damage such as storm surge should occur in this area, the disaster would be a long-term catastrophe. On the coast of Tokyo Bay, countermeasures have been taken by tide embankments and floodgates. However, considering the damage scale when it occurs, an analysis in this area is very important. In this area, ground settlement occurred and groundwater head dropped because groundwater excessively withdrew by the industrial purpose during the period of economic growth. Currently, the groundwater head recovers and the ground settlement has been subsided. However, due to the groundwater head fluctuation, pore water pressure distribution had been different from hydrostatic pressure distribution. Therefore, in the analysis in this area, it is necessary to consider past groundwater head fluctuation. In this research, the ground settlement and the distribution of pore water pressure are simulated from groundwater level fluctuation over the past 100 years. Then, we conducted the seismic analysis by input the distribution of effective stress calculating from the simulated ground water pressure. The sites analyzed in this research are Tokyo Sea Life Park at the mouth of Arakawa River.
Tech Reviews Ltd, 15 May 2019, Journal of Civil Engineering and Construction, 8 (2), 41 - 47, English[Refereed]
Scientific journal
- Oxford University Press (OUP), 01 Mar. 2019, Geophysical Journal International, 216 (3), 1890 - 1900, English
[Refereed]
Scientific journal
- Mar. 2019, 都市安全研究センター研究報告, (23), 37 - 54, Japanese不飽和土の締固め曲線と硬化則の関連性について
Research institution
- Mar. 2019, 都市安全研究センター研究報告, (23), 26 - 36, Japanese深海底プレート境界デコルマ帯を想定した過圧密化の発現
Research institution
- Feb. 2019, Journal of Civil Engineering and Construction, 8 (1), 13 - 18, English
[Refereed]
Scientific journal
- 土木学会, 2019, 土木学会論文集（F部門）, 75 (1), 31 - 39, Japanese
[Refereed]
Scientific journal
The migration of contaminant through soil is usually modeled using the advection-dispersion equation and assumes that the porous media is stationary without introducing a constitutive equation to represent soil structure. Consequently, time-dependent deformation induced by soil consolidation or physical remediation is not considered, despite the need to consider these variables during planning for the remediation of contaminated ground, the prediction of contaminated groundwater movement, and the design of engineered landfills. This study focuses on the numerical modeling of solute transfer during consolidation as a first step to resolve some of these issues. We combine a coupling theory-based mass conservation law for soil-fluid-solute phases with finite element modeling to simulate solute transfer during deformation and groundwater convection. We also assessed the sensitivity of solute transfer to the initial boundary conditions. The modeling shows the migration of solute toward the ground surface as a result of ground settlement and the dissipation of excess pore water pressure. The form of solute transport is dependent on the ground conditions, including factors such as the loading schedule, contamination depth, and water content. The results indicate that an understanding of the interaction between coupling phases is essential in predicting solute transfer in ground deformation and could provide an appropriate approach to ground management for soil remediation.
WILEY, Jul. 2018, INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, 42 (10), 1172 - 1196, English[Refereed]
Scientific journal
- 2018, Proceedings of the 7th International Conference on Unsaturated Soils, EnglishNumerical analysis of vacuum consolidation considering dissolved gasses
[Refereed]
International conference proceedings
Currently, finite element codes for small-strain have been widely applied in geotechnical engineering problems. However, the limitations of these codes are recognized, especially when the strain is large. To overthrow such limitations, finite-strain finite element code for porous media is needed. Therefore, this study aims to implement the finite element code for coupled solid-fluid at finite strain for static and dynamic problems. Firstly, the governing equation for porous media at finite-strain was introduced. Then, the mixed formulation of both phases with respect to the reference coordinates by deriving the governing equations with respect to the reference or current coordinates and by considering the solid and fluid as separate, was given. At present, the code is developed only for elastic regime as its preliminary step. In this study, the proposed code has been verified with the static and dynamic problem. And, the result of the finite-strain finite element code is then compared with the result of the analytical solution and small-strain finite element code within the small-strain regime. Thereafter, the proposed code was used to estimate the response of the earthen dam when subjected to a dynamic load. Finally, the results, discussion, and comparison between small- and finite-strain finite element analyses were presented.
GEOMATE International Society, 2018, International Journal of GEOMATE, 15 (51), 1 - 8, English[Refereed]
Scientific journal
In view of the need to utilize ocean space and to develop seabed resources, the assessment of the stability of deep seabed soil has emerged as an important challenge in the field of geomechanics. To study seabed stability, the strength and stiffness of the natural ground must be ascertained. Accordingly, it is necessary either to conduct laboratory testing on soil specimens sampled from the seabed or to estimate the strength and stiffness by in-situ tests. While in the future it may be reasonable to conduct in-situ tests to estimate the stiffness and strength of seabed soil, it will still be necessary to compare the physical properties measured by in-situ testing with those measured by laboratory testing in advance of these determinations. In short, soil specimens must be sampled from the actual deep seabed, and laboratory mechanical tests must be conducted on the sampled soil specimens. However, soil sampled from the ocean bottom is subject to effects that differ from those exerted on soil sampled from the earth. More specifically, the non-negligible effects of disturbance are expected with soil sampled from the ocean bottom. The effects of disturbance occur during the sampling process due to the vaporization of dissolved gases, as these soil specimens are under relatively higher pressure and contain pore water with a high amount of dissolved gases. Therefore, numerical simulations were conducted in the present study to investigate the effects of vaporized dissolved gases on the mechanical behavior of soil specimens during sampling and on the undrained shear strength as determined by laboratory tests. The analyses revealed that the combination of the decreasing effective stress caused by the sampling and factors such as overconsolidation and unsaturation is attributable to the difference between the soil strength ascertained by laboratory testing and the in-situ soil strength.
Japanese Geotechnical Society, 2018, Soils and Foundations, Vol.58 (No.3), pp.689 - 701, English[Refereed]
Scientific journal
Bentonite materials have been considered as a candidate material for engineered barriers in transuranium (TRU) waste disposal facilities due to their physical and chemical characteristics. Bentonite materials will be initially compacted and unsaturated. After closing the cavern, the bentonite material will become saturated through exposure to a percolating groundwater. It is therefore important to understand the behaviour of bentonite during saturation, which provides an initial condition of the disposal facilities. This paper explains a mathematical model which can express the saturation process. Subsequently, a series of numerical simulations were carried out. First, the swelling pressure of buffer and backfill was examined to verify the numerical model. It was confirmed that the simulated swelling pressure rises with water absorption, and swelling pressure test results from the literature are shown to be satisfactorily predicted by the numerical model, although these were slightly overestimated. Next, the mechanical behaviour of bentonite materials in a TRU waste disposal facility during the saturation process was examined using soil/ water/ air coupled finite-element method. Although it is difficult to examine the validity of analysis results because of the difficulty of an extremely long-term measurement, the qualitative behaviour of the saturation process could be inferred.
ICE Publishing, Oct. 2017, Environmental Geotechnics, 4 (5), 339 - 352, English[Refereed]
Scientific journal
The impermeability of bentonite is dependent on montmorillonite microstructures and varies with chemical alteration caused by related changes. The Kozeny-Carman equation is viewed as a rational hydraulic model for bentonite because it incorporates microstructure parameters such as specific surface area in addition to macrostructure parameters such as the void ratio. In the study reported here, a technique for measuring the specific surface area of compacted bentonite under constant volume conditions using X-ray diffraction was developed, and the hydraulic conductivity of various bentonite materials was evaluated based on the measurements thus obtained. The applicability of the Kozeny-Carman hydraulic model for evaluation of impermeability of bentonite was clarified. (C) 2017 Production and hosting by Elsevier B.V. on behalf of The Japanese Geotechnical Society.
JAPANESE GEOTECHNICAL SOC, Oct. 2017, SOILS AND FOUNDATIONS, 57 (5), 683 - 697, English[Refereed]
Scientific journal
- Sep. 2017, Proc. 19th International Conference on Soil Mechanics and Geotechnical Engineering, pp.1113 - 1120, EnglishTC106 General Report; Unsaturated Soils
[Refereed]
International conference proceedings
- May 2017, Proc. of 2nd Annual Workshop of the Cebama Project, EnglishH-M-C coupling analysis considering several scenarios of long-term alteration in cement-bentonite system
[Refereed]
International conference proceedings
- Mar. 2017, 都市安全研究センター研究報告, (21), 27 - 35, Japanese地盤動的解析のための試験結果のばらつきを考慮したパラメータ範囲の検討
Research institution
- Mar. 2017, 都市安全研究センター研究報告, (21), 36 - 48, Japanese海底地盤におけるサンプリング時の応力解放に伴う乱れに関する検討
Research institution
- Mar. 2017, 都市安全研究センター研究報告, (21), 83 - 90, Japanese化学変質を考慮したベントナイト緩衝材の長期挙動評価
Research institution
- Mar. 2017, 都市安全研究センター研究報告, (21), 73 - 82, Japaneseデコルマ帯における変質を考慮したせん断挙動モデル
Research institution
- Mar. 2017, 都市安全研究センター研究報告, (21), 63 - 72, Japaneseジオテキスタイル補強土の補強効果の評価手法
Research institution
- Mar. 2017, 都市安全研究センター研究報告, (21), 49 - 62, JapaneseB 値に与える影響因子とB 値測定手法がせん断挙動に及ぼす影響
Research institution
Bentonite has remarkable swelling characteristics and low permeability that enhance the stability of the buffer materials in repositories for the geological disposal of radioactive waste. It is necessary to apply reliable numerical simulation techniques to assess the safety and mechanical stability of repositories over a long period of time. Having a constitutive model that can describe the mechanical behavior of bentonite is key to such numerical simulations. This paper proposes an elasto-plastic constitutive model to describe the changes in the mechanical properties of bentonite due to saturation in the progress of a repository becoming submerged under groundwater. In the proposed model, the swelling index is formulated as a function of the degree-of-saturation to express not only the swelling behavior, but also the dependency of the degree-of-saturation on the dilatancy characteristics. The montmorillonite content is used as a material parameter to determine the normal consolidation line. The experimental results of swelling volume and swelling pressure tests in previous literature are shown to have been satisfactorily predicted by the proposed model. (C) 2017 Production and hosting by Elsevier B.V. on behalf of The Japanese Geotechnical Society.
JAPANESE GEOTECHNICAL SOC, Feb. 2017, SOILS AND FOUNDATIONS, 57 (1), 80 - 91, English[Refereed]
Scientific journal
- 2017, BEACON Initial Workshop, EnglishResearch activities at RWMC on the bentonite re-saturation process (2) Laboratory and numerical evaluation
[Refereed]
International conference proceedings
- 2017, 7th International Conference on Clays in Natural and Engineered Barriers for Radioactive Waste Confinement, EnglishElastoplastic prediction of clay-buffer homogenization due to swelling behavior
[Refereed]
International conference proceedings
- 地盤工学会, 2017, 環境地盤工学シンポジウム論文集, Vol.12, 567 - 570, Japanese地層処分施設内における温度・密度・飽和度を考慮したベントナイト緩衝材の力学特性
[Refereed]
Symposium
- 地盤工学会, 2017, 環境地盤工学シンポジウム論文集, Vol.12, 557 - 560, Japanese水質の違いによるベントナイトの膨潤特性
[Refereed]
Symposium
- 2017, 土木学会論文集 A2 (応用力学), 73 (2), I_489 - I_496, Japanese解析による施工時期の違いが盛土の初期応力に与える影響
[Refereed]
Scientific journal
- 2017, Proceedings of the First Annual Workshop of the HORIZON 2020 CEBAMA Project, 269 - 274, English
[Refereed]
International conference proceedings
- 2017, Proc. of Computational Engineering Conference JSCE, Vol.22, EnglishDetailed FE analysis of E-Defense shake table test on soil-underground structure
[Refereed]
International conference proceedings
- Nov. 2016, Proc. of 6th Int. Conf. GEOMATE 2016, 233 - 238, EnglishExpression of air pressure distribution using soil/water/air coupled analysis
[Refereed]
International conference proceedings
The B-value, measured after setting up a specimen for triaxial testing, is used for evaluating the degree of saturation of a specimen. However, the stress conditions used when measuring the B-value have not been standardized. Although some experimental approaches have been pursued, no detailed analyses have evaluated the effects of the measurement conditions on the B-value results. In this study, the B-values of nearly saturated specimens under various stress conditions were investigated, using a smart triaxial test apparatus capable of elaborate stress control, and comparisons among measurement results were conducted. Moreover, by applying Henry's law, which governs the dissolution of the gas phase into the liquid phase, to an existing constitutive model for unsaturated soil, a new soil model was proposed. This new model accurately represents the behaviors of pore air even under nearly saturated conditions. In addition, the effects of the stress conditions on the B-values were investigated through numerical simulations of B-value measurements. (C) 2016 The Japanese Geotechnical Society. Production and hosting by Elsevier B.V.
JAPANESE GEOTECHNICAL SOC, Oct. 2016, SOILS AND FOUNDATIONS, 56 (5), 848 - 860, English[Refereed]
Scientific journal
- 土木学会, Jun. 2016, 土木学会論文集C (地圏工学), 72 (2), 164 - 178, Japanese放射性廃棄物の地下空洞型物処分施設に用いる側部低透水層の転圧工法による施工品質の評価
[Refereed]
Scientific journal
- Mar. 2016, 都市安全研究センター研究報告, (20), 32 - 39, Japanese
Research institution
- Mar. 2016, 都市安全研究センター研究報告, (20), 18 - 31, Japanese
Research institution
- Jan. 2016, Japanese Geotechnical Society Special Publication (The 15th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering), 2 (49), p. 1714 - 1717, English
[Refereed]
Scientific journal
- 地盤工学会, 2016, 地盤工学シンポジウム論文集, Vol.60, pp.213 - 216, Japanese木造低層住宅の地震時における完全倒壊を防止するための屋外設置フレームの提案
[Refereed]
Symposium
Most onshore earth structures, such as earthen dams, embankment, and river levees, are constructed by compaction. Transportation geotechnics also includes construction of compacted earth structures, such as road and railway embankment. Optimum compaction can increase shear strength, while decreasing compressibility and permeability of earth structures. For this reason, compaction has been used for earthworks since the dawn of times. Generally, a series of lab compaction tests is conducted to obtain a compaction curve before constructing these structures. The shape of the compaction curve, which determines the maximum dry density at the optimum water content, is very important in the design and construction of structures. However, it is difficult to control compaction quality on the basis of lab tests alone, as soil materials are inhomogeneous. Furthermore, there are differences in the compaction methods used in lab tests and at construction sites. Therefore, it is necessary to explain the mechanisms of compaction in the framework of soil mechanics. In this study, compaction of earthworks is simulated in a similar way. The effect of compaction layer thickness and the number of compaction layers on the distribution of dry densities in an earth structure was investigated through soil/water/air coupled simulation. Consequently, it was found that multi-layered compaction can create a gap in the dry density between two layers and that this gap can be reduced by thinner layer compaction. On the other hand, though the average dry density in a compacted earth structure can be increased by increasing the number of compacted layers, some gap between compaction layers was inevitable. Through these findings, this study contributes to the performance design of compacted earth structures.
ELSEVIER SCIENCE BV, 2016, ADVANCES IN TRANSPORTATION GEOTECHNICS III, 143, 276 - 283, English[Refereed]
International conference proceedings
- Dec. 2015, Proc. of Int. Conf. on Soft Ground Engineering, pp.553 - 559, EnglishInfluence of stress release after sampling on shear characteristics
[Refereed]
International conference proceedings
- Mar. 2015, 都市安全研究センター研究報告, (19), 85 - 100, Japanese弾塑性動的地盤モデルのためのパラメータの同定
Research institution
- Mar. 2015, 都市安全研究センター研究報告, (19), 75 - 84, Japanese粒度分布に注目した土粒子吸着物質の除去方法の検討
Research institution
- Mar. 2015, 都市安全研究センター研究報告, (19), 67 - 74, Japanese土/水/空気連成解析によるキャピラリーバリアシステムの性能評価
Research institution
- Mar. 2015, 都市安全研究センター研究報告, (19), 59 - 66, Japaneseベルセロ法を用いた高容量テンシオメータの開発
Research institution
- Mar. 2015, 都市安全研究センター研究報告, (19), 45 - 58, Japanese深海底デコルマ帯におけるせん断破壊モデル
Research institution
- Mar. 2015, 都市安全研究センター研究報告, (19), 28 - 44, Japanese放射性廃棄物地層処分におけるベントナイト緩衝材の変質評価手法の開発
Research institution
- Mar. 2015, 都市安全研究センター研究報告, (19), 10 - 27, Japanese廃砂堆積場の表面止水層性能評価
Research institution
- 2015, 土木学会論文集 C (地圏工学), 71 (3), 147 - 162, Japanese
[Refereed]
Scientific journal
- 公益社団法人 土木学会, 2015, 土木学会論文集A2（応用力学）, 71 (2), I_605 - I_612, Japanese深海底プレート境界デコルマ帯におけるせん断破壊モデル
[Refereed]
Scientific journal
- 公益社団法人 土木学会, 2015, 土木学会論文集A2（応用力学）, 71 (2), I_171 - I_180, Japanese
[Refereed]
Scientific journal
In recent years, enormous damage has been caused by natural disasters. Disaster Medical Assistance Team (DMAT) play an important role in minimizing human suffering. However, since factual information is intermingled with disinformation in the event of a disaster, it is difficult to obtain correct information, such as where and to what extent medical care is required, in order to dispatch DMAT appropriately. In this study, using a victims estimation formula empirically derived from the cumulative death toll data with the passage of time in past seismic hazard, an optimization problem was addressed to minimize the number of deaths.
Japan Society of Civil Engineers, 2015, Journal of Japan Society of Civil Engineers, Ser. F6 (Safety Problem), 71 (1), 32 - 45, Japanese
Consequently, it was found that early dispatch of DMAT would be effective, and DMAT should be dispatched according to the circumstances (number of DMAT, conditions of affected areas) in order to minimize the cumulative death toll. And, by setting the conditions of the affected area, it was possible to consider the way of reasonable DMAT dispatch. Thus, it has become possible to suggest the way of effective dispatch of finite DMAT, to use limited DMAT resources efficiently, and to help make decisions.[Refereed]
Scientific journal
Decision makers must decide the disaster correspondence by using uncertain information. When the decision maker makes this decision, they have the dilemma to prioritize which of “the rapidity of correspondence” and “the accuracy of information”. The result for disaster varies according to the difference in priority.
Japan Society of Civil Engineers, 2015, Journal of Japan Society of Civil Engineers, Ser. F6 (Safety Problem), 71 (1), 46 - 57, Japanese
This study approximate the change of cumulative number of death with time lapse by using the Weibull distribution and proposed the Bayesian estimation model to predict the total number of deaths by utilizing the change of cumulative number of deaths. By considering the estimated total number of deaths with past earthquakes cases, it was possible to estimate the time period to make the disaster response decision. Therefore, this would be a judgment material to reduce the dilemma of decision makers.[Refereed]
Scientific journal
- Japan Society of Civil Engineers, 2015, Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM)), 71 (2), I_429 - I_436, Japanese
[Refereed]
Scientific journal
- Numerical simulation of saturation process in TRU disposal facility
Due to its low permeability and excellent expansion characteristics, bentonite materials are considered to be the engineered barrier in Trans-Uranium (TRU) disposal facility. It is necessity to predict the mechanical behavior of bentonite using numerical simulation to evaluate the long-term performance of TRU disposal facility. In this paper, we simulated the saturation process of bentonite materials in TRU disposal facility from an initially unsaturated state. And we examined the mechanical behavior of bentonite buffer during the saturation process. This simulation result shows that Disposal waste is moved upward due to the difference of swelling pressure between buffer and backfill. And the facility existed in unsaturated state even under steady state conditions due to the entrapped air.
CRC PRESS-TAYLOR & FRANCIS GROUP, Sep. 2014, Computer Methods and Recent Advances in Geomechanics, 409 - 414, English[Refereed]
International conference proceedings
- Expression of the pore-pressure coefficient B with numerical simulation
Undrained shear strength is used for estimating the bearing resistance of foundations and the safety factor of a slope. For this test, the pore-pressure coefficients, namely A and B as proposed by Skempton, are available. These coefficients can be obtained from the undrained triaxial test. According to Terzaghi's effective stress theory, the B-value must be 1.0 in a saturated soil. Therefore, a B-value of 1.0 is used as the target for saturating a specimen. However, it is difficult to achieve a B-value of 1.0 in the triaxial test. Because of this, a specimen with a B-value greater than 0.95 is regarded as saturated. The relationship between saturation and the B-value is still not clear. In this study, the factors influencing the B-value were numerically investigated with a soil/water/air coupled model that considers the solvability of pore-air to pore-water. Consequently, the pore-water pressure behavior, which depends on the initial degree of saturation and initial stress conditions, could be expressed.
CRC PRESS-TAYLOR & FRANCIS GROUP, Sep. 2014, Computer Methods and Recent Advances in Geomechanics, 403 - 408, English[Refereed]
International conference proceedings
- Derivation of mass transfer model for unsaturated soil and its applications
In this study, we use conservation laws to construct a method for describing the movement of dissolved material. This is then applied to a mathematical model. Recently, soil pollution, induced by toxic materials in the ground water, is spreading. The mobility modes for this dissolved material can be divided into advection, induced by distribution of fluid head, and dispersion, induced by distribution of concentration content. First, Darcy's law is derived from the momentum conservation law using Bear's theory. Secondly, the concept of total fluid head is extended for application to various fluids. Additionally, an infiltration equation and an advection-dispersion equation are derived from mass conservation laws. Coupling the two equations, we construct a mass transfer model for unsaturated/saturated ground. Using the model, the effect of density flow is considered assuming basic one-dimensional areas. The results show that mobility of the dissolved material depends on its density. We concluded that density flow dominates along the vertical rather than the horizontal direction and mobility of the fluid is dulled in the unsaturated area.
CRC PRESS-TAYLOR & FRANCIS GROUP, Jul. 2014, Proc. International Conference on Unsaturated Soils: Research and Applications (UNSAT2014), Vol.2, 1179 - 1187, English[Refereed]
International conference proceedings
- Application of soil/water/air coupled FE code to predict seepage and deformation on sandy slope
In order to study the triggering factors for shallow landslides during rainfall, sandy soil slopes were prepared in laboratory angles of 30 and 45 degrees and those slopes were poured with rainfall intensities of 30 and 60 mm/hours through a specially developed rain simulator. Moreover, the rainfall on slope was simulated with using unsaturated soil/water/air coupled F.E. code, and the numerically calculated depth of water front and values of suction at different location in the slopes at various angles of inclinations matched well with the experimentally observed values. The combined results obtained with the numerical and experimental studies were utilized to predict the variation in the depth of water and values of suction at different intensities of rainfall as well as deformation of slopes during rainfall.
CRC PRESS-TAYLOR & FRANCIS GROUP, Jul. 2014, Proc. International Conference on Unsaturated Soils: Research and Applications (UNSAT2014), Vol.1, 621 - 627, English[Refereed]
International conference proceedings
- CRC Press, 05 Jun. 2014, Proc. International Conference on Unsaturated Soils: Research and Applications (UNSAT2014), 1, 659 - 665, English
[Refereed]
In book
- CRC Press, 05 Jun. 2014, Proc. International Conference on Unsaturated Soils: Research and Applications (UNSAT2014), 1, 545 - 552, English
[Refereed]
In book
- Apr. 2014, 骨材資源, 185, 13 - 23, Japaneseマルチング材料としての粉砕汚泥焼成煉瓦の有効活用について
[Refereed][Invited]
Scientific journal
- 神戸大学都市安全研究センター, Mar. 2014, 神戸大学都市安全研究センター研究報告, (18), 44 - 53, Japanese
Research institution
- 神戸大学都市安全研究センター, Mar. 2014, 都市安全研究センター研究報告, (18), 40 - 43, Japanese
Research institution
- 神戸大学都市安全研究センター, Mar. 2014, 都市安全研究センター研究報告, (18), 23 - 31, Japanese
Research institution
- 神戸大学都市安全研究センター, Mar. 2014, 都市安全研究センター研究報告, (18), 32 - 39, Japanese
Research institution
- BGR, Feb. 2014, Proc. International Conference on the Performance of Engineered Barriers: Backfill, Plugs & Seals, Physical and Chemical Properties, Behaviour & Evolution, EnglishCoupled Hydraulic-Mechanical-Chemical Modeling for Cement-Bentonite Barrier System (2) Mechanical Modeling of Bentonite Engineered Barrier in Consideration of Long Term Chemical Alteration
[Refereed]
International conference proceedings
- 地盤工学会, 2014, 地盤工学シンポジウム論文集, Vol.59, pp.163 - 170, Japanese東名牧の原盛土の崩壊時強度の推定と今後の維持管理への提言
Symposium
The pore pressure coefficient B, which is measured on triaxial test, is useful for evaluating degree of saturation of specimen. However, the influential factors on this B value other than degree of saturation have not been investigated in detail up to now. In this study, first, Henry's law that indicates dissolved air in pore water was applied to the existing constitutive model for unsaturated soil in order to express the behavior of pore air on unsaturated soil extremely close to fully saturated state. Next, the influential factors, such as degree of saturation, confining stress and back pressure, were investigated through numerical simulations with using newly obtained model. Consequently, it was found out that B value depends on not only degree of saturation but also stress state.
Japan Society of Civil Engineers, 2014, Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM)), 70 (2), I_145 - I_153, Japanese[Refereed]
Scientific journal
- 地盤工学会, 2014, 地盤工学シンポジウム論文集, Vol.59, pp.115 - 120, Japanese新しい三軸試験装置の紹介 : SMART triaxial testing apparatus
Symposium
The East Japan Earthquake and Tsunami caused serious damages in the coastal area of eastern Japan. Many houses and cars on the road were swept away by the tsunami. Also, industrial facilities such as chemical plants in the coastal area were completely destroyed. Damage from saline seawater was not limited only to the rice field areas, and there were also serious anxieties regarding the possibility of ground contamination as a result of harmful heavy metals that leaked from destroyed chemical plants. In light of this scenario, we carried out a quantitative survey to examine these areas. This paper reports on the results of our survey. It was found that high salt concentrations were detected on the ground surface but predictions state that these concentrations can be diluted with rainfall. It was also revealed that serious ground contamination due to the harmful heavy metals was not detected.
2014, Theoretical and Applied Mechanics Japan, 62, 141 - 148, English[Refereed]
Scientific journal
Recently, the hydraulic/mechanical/chemical (HMC) analytical method has been studied with the aim of evaluating the long-term performance of Trans-Uranium (TRU) geological repositories. In this particular research, the hydraulic/mechanical modelling of bentonite materials for HMC analyses has been studied, with bentonite materials considered as the engineered barrier. It is said that the bentonite material in the TRU disposal facilities is altered chemically by cement leachate. Moreover, there is a concern that chemical alteration changes the expansion characteristics and water permeability of the bentonite material. In this paper, using past test results, the influence of montmorillonite content and the exchange of sodium and calcium ions on mechanical and hydraulics behaviour is examined. Hydraulic/mechanical mathematical modelling is also presented, describing the mechanical behaviour of bentonite from an initially unsaturated state while also taking into account the hydraulic and mechanical characteristics of bentonite mentioned above. We also simulate the saturation process from an initially unsaturated state in a TRU disposal facility, which is modelled one-dimensionally.
GEOLOGICAL SOC PUBLISHING HOUSE, 2014, CLAYS IN NATURAL AND ENGINEERED BARRIERS FOR RADIOACTIVE WASTE CONFINEMENT, 400, 221 - 235, English[Refereed]
Scientific journal
In order to evaluate the long-term behaviour of the engineered barriers in geological disposal sites for transuranic element-bearing (TRU) waste, an evaluation by numerical analysis is required. Although chemical and hydraulic/mechanical analyses have been conducted independently until now, essentially both type of phenomena occur simultaneously and produce synergistic effects. Therefore, we focused attention on the buffer (bentonite) engineered barrier and conducted a study of which involved incorporating hydraulic/mechanical phenomena into the chemical analysis of bentonite alteration. The simulations employed weakly-coupled chemical and hydraulic/mechanical effects to study the behaviour in one dimension. The results showed that the dissolution of the montmorillonite is suppressed in the buffer section nearest the cement material. Moreover, in order to achieve a fully coupled analysis in future, the present study also identifies issues that need to be resolved.
MINERALOGICAL SOC, May 2013, Clay Minerals - Journal of Fine Particle Science, 48 (2), 331 - 341, English[Refereed]
Scientific journal
- 神戸大学都市安全研究センター, Mar. 2013, 神戸大学都市安全研究センター研究報告, (17), 31 - 38, Japanese
Research institution
- Mar. 2013, 都市安全研究センター研究報告, (17号), 23 - 30, Japanese災害派遣医療チームの配置モデルに関する考察
Research institution
- 神戸大学都市安全研究センター, Mar. 2013, 神戸大学都市安全研究センター研究報告, (17), 49 - 60, Japanese
Research institution
- 神戸大学都市安全研究センター, Mar. 2013, 神戸大学都市安全研究センター研究報告, (17), 39 - 48, Japanese
Research institution
- Japan Chapter of International Geosynthetics Society, 2013, Geosynthetics Engineering Journal, 28 (0), 109 - 116, Japanese
[Refereed]
Scientific journal
© Springer Science+Business Media Dordrecht 2013. In this chapter, the stress–strain relationship on the singular point of the yield surface of the original Cam clay model and the Sekiguchi-Ohta’s model is derived in order to compute the volume change correctly. Metastable space, the range of increment of strain in which effective stress does not get away from the singular point of yield surface, was theoretically derived. In metastable space, the increment of volumetric strain is larger than the increment of deviatoric strain.
2013, Geotechnical, Geological and Earthquake Engineering, 25, 229 - 239[Refereed]
In book
© Springer Science+Business Media Dordrecht 2013. An elasto-plastic constitutive model for unsaturated soils is improved to realize numerical stability of computations at the singular point on the yield surface and an accurate prediction of the mechanical behavior of overconsolidated (or elastic state) soils in this chapter. The authors introduce the exponential contractancy model (EC model) by Ohno et al. (J Appl Mech JSCE 9:407–414, 2006) and the subloading surface model by Hashiguchi and Chen (Int J Numer Anal Method Geomech 22:197–227, 1998) to the elasto-plastic constitutive model for unsaturated soils by Ohno et al. (J JSCE 63(4):1132–1141, 2007). The applicability of the constitutive model is verified by simulating triaxial shear tests under constant net stress undrained conditions.
2013, Geotechnical, Geological and Earthquake Engineering, 25, 215 - 228[Refereed]
In book
- 土木学会, 2013, 土木学会論文集C（地圏工学）, Vol.69 (No.4), pp.404 - 416, Japanese
[Refereed]
Scientific journal
- Expression of mechanical characteristics in compacted soil with soil/water/air coupled F.E. Simulation
Results obtained in a lab compaction test are difficult to apply to the design and compaction control at an actual geotechnical engineering site. This is attributed to the fact that the mechanism for compaction has not been explained using the principles of soil mechanics. The main theme of this study is interpretation of the compaction mechanism with unsaturated soil mechanics. Here, static compaction tests were simulated with soil/water/air coupled finite element analysis code DACSAR-MP. Consequently, the shape of the compaction curve was successfully expressed. Moreover, the effects of compaction on compressibility and permeability of compacted soil could be reasonably explained. Additionally, shear deformation was applied to the specimen obtained from static compaction simulations in soil/water/air coupled analysis. The relationships between shear strength and compaction curve showed good agreement with the actual behavior.
2013, Proc. Int. Conf. on Soil Mechanics and Geotechnical Engineering, 1, 1129 - 1132, English[Refereed]
International conference proceedings
- Oct. 2012, Proc. 5th Clays in Natural and Engineered Barriers for Radioactive Waste Confinement,, EnglishEvaluation of long-term interaction between cement and bentonite for geological disposal, (4) Chemical alteration analysis of bentonite in consideration of hydraulic/mechanical properties
[Refereed]
International conference proceedings
- Oct. 2012, Proc. 5th Clays in Natural and Engineered Barriers for Radioactive Waste Confinement, EnglishEvaluation of long-term interaction between cement and bentonite for geological disposal, (4) Effect of montmorillonite content on mechanical and hydraulics properties of bentonite and its numerical modeling
[Refereed]
International conference proceedings
- The GEOMATE International Society, Sep. 2012, International journal of GEOMATE : geotechnique, construction materials and environment, 3 (1), 357 - 362, EnglishAn Interpretation of Mechanical Properties of Bentonite as a Non-linear Elastic Material
[Refereed]
Scientific journal
- 神戸大学都市安全研究センター, Mar. 2012, 神戸大学都市安全研究センター研究報告, (16), 45 - 54, Japanese
Research institution
- 神戸大学都市安全研究センター, Mar. 2012, 神戸大学都市安全研究センター研究報告, (16), 23 - 32, Japanese
Research institution
- 神戸大学都市安全研究センター, Mar. 2012, 神戸大学都市安全研究センター研究報告, (16), 33 - 43, Japanese
Research institution
- 神戸大学都市安全研究センター, Mar. 2012, 神戸大学都市安全研究センター研究報告, (16), 63 - 74, Japanese
Research institution
- Mar. 2012, Proc. 5th Asia-Pacific Conference on Unsaturated Soils (AP-UNSAT2011), 31 - 44, EnglishThe role of unsaturated geomechanics in desertification due to salt damage
[Refereed]
International conference proceedings
- Mar. 2012, Proc. 5th Asia-Pacific Conf. on Unsaturated Soils, 287 - 292, EnglishMathematical model of soil/water/air coupled problem for unsaturated soils considering mass transfer within pore-water
[Refereed]
International conference proceedings
- Mar. 2012, Proc. 5th Asia-Pacific Conf. on Unsaturated soils, 489 - 494, EnglishExpression of self-hardening property of coal fly-ash
[Refereed]
International conference proceedings
- 2012, Proc. of 2nd Int. Conf. GEOMATE 2012, 828 - 833, EnglishProtective measures of the monumental pine in Rikuzentakada with soil-water-air-solved material coupled model
[Refereed]
International conference proceedings
- 2012, Proc. of 2nd Int. Conf. GEOMATE 2012, 666 - 671, EnglishAn interpretation of mechanical properties of bentonite as a non-linear elastic material
[Refereed]
International conference proceedings
- 2012, Proc. of 2nd Int. Conf. GEOMATE 2012, 391 - 396, EnglishInfluences of soil material parameters in compaction simulation with soil/water/air coupled F. E. code
[Refereed]
International conference proceedings
- Springer Berlin Heidelberg, 2012, Unsaturated Soils: Research and Applications, 181 - 187, English
[Refereed]
In book
- Japan Society of Civil Engineers, 2012, 土木学会論文集A2(応用力学), 68 (2), I_307 - I_315, Japanese
[Refereed]
Scientific journal
- Japan Society of Civil Engineers, 2012, 土木学会論文集A2(応用力学), 68 (2), I_345 - I_352, Japanese
[Refereed]
Scientific journal
Compacted soil is widely used for earth structures. However, the mechanism of compaction has not been explained, so it is difficult to grasp distributions of stress, void ration, and soil moisture within compacted earth structure. Therefore, estimation of safety and stability of compacted earth structures exposed to natural disaster is complicated. Compaction is decreasing void ratio by applying stress under certain water content and pushing air out of soil mass. Thus, the mechanics of unsaturated soil, which includes air within void, is needed for understanding of compaction. In this study, we regarded compaction as compression and expansion phenomenon of unsaturated soil under drained air and undrained water conditions and formulated it in initial-boundary-value problem. Here, the influences of permeability and soil water retention characteristics on compaction were considered and static compaction tests were simulated. Moreover, multi-layered compaction was examined.
Japan Society of Civil Engineers, 2012, Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM)), 68 (2), I_299 - I_306, Japanese[Refereed]
Scientific journal
- Japan Society of Civil Engineers, 2012, 土木学会論文集A2(応用力学), 68 (2), I_291 - I_298, Japanese
[Refereed]
Scientific journal
- Elasto-plastic constitutive model for expansive soils with a concept of fully saturation curve
This study presents a new constitutive model for expansive soils. Under any arbitrary state of degree-of-saturation, the mechanical void ratio predicted by the elasto-plastic constitutive models, i.e. EC model and Se-hardening model are combined with the additional void ratio in order to characterize the typical swelling behavior of expansive soil. Herein, the fully saturation curve which derived from compaction and consolidation experimental tests are taken into consideration. The proposed model is examined by simulating the typical experimental test on expansive soil, i.e. normally consolidation and swelling pressure tests. © 2012 IEEE.
2012, 5th Asia-Pacific Conference on Unsaturated Soils 2012, 1, 303 - 308, English[Refereed]
International conference proceedings
- Japan Society of Civil Engineers, Sep. 2011, 土木学会論文集A2（応用力学論文集）, 14, I_231 - I_240, Japanese
[Refereed]
Scientific journal
Static friction in granular wedges can stabilize own weight on a horizontal plane without lateral supports. This sort of problem provides fundamental knowledge about pressure distribution along the foundation of earth works which have a long triangular shape in particular. The present study reviews the authors' recent development on an analytic model of a sand heap which adopted Nadai's hypothesis on the major principal stress orientation and a framework of below-yielding limit. Because deformation analyses of many geotechnical engineering problems often require the magnitude of coefficient of lateral earth pressure at-rest K-0 to describe in situ lateral earth pressure, emphasis is placed on the evaluation of stress ratio under the apex of sand heap which represents Jaky's basic assumption on the derivation of K-0 in the prismatic sand heap sloped at an angle of repose. Comparison of the analytical stress ratio along the central plane of granular wedge with Jaky's expressions was reported.
IOS PRESS, Sep. 2011, Proc. International Symposium on Deformation Characteristics of Geomaterials (IS-Seoul 2011), Vol.2, 924 - 932, English[Refereed]
International conference proceedings
- 神戸大学都市安全研究センター, Mar. 2011, 神戸大学都市安全研究センター研究報告, (15), 51 - 58, Japanese
Research institution
- 神戸大学都市安全研究センター, Mar. 2011, 神戸大学都市安全研究センター研究報告, (15), 21 - 28, Japanese
Research institution
- 神戸大学都市安全研究センター, Mar. 2011, 神戸大学都市安全研究センター研究報告, (15), 29 - 40, Japanese
Research institution
- 神戸大学都市安全研究センター, Mar. 2011, 神戸大学都市安全研究センター研究報告, (15), 13 - 20, Japanese
Research institution
- 神戸大学都市安全研究センター, Mar. 2011, 神戸大学都市安全研究センター研究報告, (15), 41 - 50, Japanese
Research institution
An evaluation method for the mechanical behavior of unsaturated soils is studied in this paper. Although the mechanical behavior of unsaturated soils is complicated, a simple modeling is preferable in practice. This is because the soil properties are not homogeneous and ground data is limited when structures are being designed. In addition, in order to evaluate the reliability of the design, the physical meanings of the parameters applied in the prediction model should be clear. Firstly, the authors study the relationship between compaction curves and compression indexes in the unsaturated state that is used in the proposed constitutive model. Based on the constitutive model, the stress paths for constant volume shear tests are formulated under a constant void ratio condition and the stress paths for undrained shear tests are calculated under a constant water content condition. In the case of unsaturated specimens, the volume of these specimens changes with the shear deformation and the stress paths depend on the initial degree of saturation. The results of the calculation qualitatively describe the test results by considering the changes in effective confining pressure in the undrained condition and the water retention curves. © 2010 Springer Science+Business Media B.V.
Mar. 2011, Geotechnical and Geological Engineering, 29 (2), 171 - 180, English[Refereed]
Scientific journal
Due to its low permeability and excellent expansion characteristics, bentonite is an excellent candidate with potential use as a buffer in the disposal of nuclear waste. Its expansion characteristics, activated by wetting, can be interpreted based on the full saturation line, depicted as a unique line on the density and the confining pressure relationship as proposed by Kobayashi et al. (2007). In addition, its elasto-plastic constitutive relation can also be formulated by introducing additional irreversible strain component describing the expansion of the montmorillonite present in the bentonite material. A constitutive model can consistently express the mechanical behavior of the compacted bentonite material from the unsaturated to the fully saturated state. This paper describes the density homogenization process that was conducted through a series of soil-water coupled elasto-plastic finite element simulations. Specifically, bentonite specimens, with different initial densities, were permeated with a constant water head. Stresses and strains developing in bentonite, particularly the density change, were carefully examined. A series of numerical simulations, performed on the two specimens, showed that specimens did not homogenize to a unique value of density upon reaching the fully saturated state. To confirm the simulation results, we carried out a series of experiments. The experimental results also support our simulation results. Copyright © 2011 by ASME.
2011, Proceedings of the International Conference on Radioactive Waste Management and Environmental Remediation, ICEM, (PARTS A AND B), 949 - 954, English[Refereed]
International conference proceedings
In structural mechanics, Nadai's sand hill analogy is the interpretation of an ultimate torque applied to a given structural member with a magnitude that is analogously twice the volume of stable sand heap which can be accommodated on a transverse cross-section basis. Nadai's analogy is accompanied by his observation of a loose triangular embankment, based on the fact that gravitating loose earth is stable if inclined just under the angle of repose. However, Nadai's analysis of stress distribution in a planar sand heap was found to be inaccurate because the total pressure obtained from Nadai's solution is greater than the self-weight calculated from the heap geometry. This raises a question about the validity of his observation in relation to the analogy. To confirm his criterion, this article presents and corrects the error found in Nadai's solution by analyzing a radially symmetric stress field for a wedge-shaped sand heap with the purpose of satisfying both force balance and Nadai's closure. The fundamental equation was obtained by letting the friction state vary as a function of angular position and deduce it under the constraint that the principal stress orientation obeys Nadai's closure. The theoretical solution sufficiently agreed with the past experimental measurements. © 2010 Elsevier Ltd. All rights reserved.
Oct. 2010, Journal of the Mechanics and Physics of Solids, 58, 1506 - 1523, English[Refereed]
Scientific journal
- Sep. 2010, 応用力学論文集, Vol.13, 363 - 370, Japanese締固め方法の違いが締固め土構造物の品質に及ぼす影響
[Refereed]
Scientific journal
- Sep. 2010, 応用力学論文集, Vol.13, 423 - 430, Japanese築堤シミュレーションにおける設定条件が盛土内応力分布に及ぼす影響
[Refereed]
Scientific journal
- Study of stratification resistant to salt damage
Desertification due to salt damage has recently become a serious problem throughout the world. Salt damage is a phenomenon where salt in the groundwater gets concentrated at the ground surface and kills vegetation. In this study salt damage due to disequilibrium of water balance was simulated with unsaturated soil/water coupled simulation code, as applied the material transport equation. Evaporation and precipitation cycles were applied to a model of ground that contained salty groundwater in its deep region. This allowed the successful reproduction of the phenomenon of salt accumulation on the ground surface. Additionally, identical climatic conditions were applied to model grounds consisting of two types of soil, different in terms of their soil-water retention characteristics. It was found that two methods of overlay and insertion of a layer of coarse-grade material, known as 'mulching', are effective in the prevention of salt accumulation. © 2011 Taylor & Francis Group, London.
Sep. 2010, Proc. 5th Int. Conf. on Unsaturated Soils, 2, 1133 - 1139, English[Refereed]
International conference proceedings
- Sep. 2010, Proc. 5th Int. Conf. on Unsaturated Soils, 965 - 971, EnglishSimulation of static compaction with unsaturated soil/water coupled F. E. analysis
[Refereed]
International conference proceedings
- Sep. 2010, Proc. 5th Int. Conf. on Unsaturated Soils, 277 - 282, EnglishMechanical behaviors and water retention characteristics of micro-porous ceramic particles produced by burning sludge
[Refereed]
International conference proceedings
- Sep. 2010, Proc. 5th Int. Conf. on Unsaturated Soils, 1337 - 1342, EnglishBanking simulation with a constitutive model for unsaturated soil
[Refereed]
International conference proceedings
- Jul. 2010, 土木学会論文集C, Vol.66 (No.3), 457 - 471, Japanese神戸空港における地盤変形解析手法の構築
[Refereed]
Scientific journal
- Jun. 2010, 土木学会論文集C, Vol. 66 (No. 2), 356 - 369, Japanese超軟弱地盤における道路盛土の変形挙動要因とその抑制対策
[Refereed]
Scientific journal
- Analyses of pressure distribution using arching criteria in 2D sand heaps
Pressure distribution in sand heaps is affected by a particular arching action during the formation process. The closure of fixed principal axes successfully links arching criterion to capture the phenomenon of central stress minimum in conical sand heaps. However, it is insufficient to explain a negligible stress dip observed in planar sand heaps, which are of practical interest to civil engineers because many earthworks are triangular in shape. This study explains the closure of polarized principal axes and the stress distribution formulation, which was found to be agreeable with experimental data. The direction of major compression along a circle traced about the apex might provide a suitable arching criterion in the 2D space of sand heaps.
2010, Theoretical and Applied Mechanics Japan, 58, 41 - 48, English[Refereed]
Scientific journal
- 2010, 神戸大学都市安全研究センター研究報告, (13), 1 - 8, Japanese不飽和土／水連成解析による築堤シミュレーション
Research institution
- A finite element simulator for mechanical behavior of unsaturated earth structures exposed to evaporation and moisturization
To predict the long-term elasto-plastic behavior of unsaturated earth structures, a constitutive model, which can express the following typical mechanical behavior of unsaturated soil, is needed. This includes shrinkage and increase of stiffness upon drying (i.e. suction increase), collapse with reduction of stiffness upon wetting (i.e. suction decrease), and the influences of suction history related to the hysteresis of soil-water retention characteristics. In this study, a new constitutive model is proposed for unsaturated soil where the effective degree of saturation is used as a parameter relating to stiffness. The model shows good agreement with experimental results. In addition, a soil/water coupled finite element simulation code (simulator), as applied to this model, is introduced. The appropriateness of the simulator is demonstrated for the case of a virtual fill.
CRC PRESS-TAYLOR & FRANCIS GROUP, Nov. 2009, Proc. 4th Asia-Pacific Conference on Unsaturated Soils, 711 - 718, English[Refereed]
International conference proceedings
- 土木学会, Sep. 2009, 応用力学論文集, 12, 429 - 436, Japanese土/水連成有限要素解析プログラムを用いた静的締固めシミュレーション
[Refereed]
Scientific journal
- Sep. 2009, 応用力学論文集, Vol.12, 187 - 194, JapaneseHPMを用いた土/水連成有限要素解析における水頭の空間離散化
[Refereed]
Scientific journal
- Stress-strain and water retention characteristics of micro-porous ceramic particles made with burning sludge
When troublesome sludge discharged from industries and purification plants are burnt by 1300 degree, they change to innocuous micro-porous ceramic materials. The authors are seeking for practical use of such micro-porous ceramic materials in the geotechnical engineering field, particularly for geohazard mitigation. Then, in order to grasp fundamental mechanical properties of the micro-porous ceramic particles, a series of laboratory tests, that is, triaxial compressive shear tests, permeability tests and water retention tests, were performed. It is found that the stress-strain characteristics and permeability of the micro-porous ceramic particles are very similar to those of standard sandy materials but they have very high water retention capability. Next, applicability of the unsaturated elasto-plastic constitutive model proposed by Ohno et al. (2007) to the mechanical behavior of micro-porous ceramic particles was examined in this paper.
CRC PRESS-TAYLOR & FRANCIS GROUP, May 2009, Proc. of the International Symposium on Prediction and Simulation Methods for Geohazard Mitigation (IS-Kyoto 2009), 339 - 345, English[Refereed]
International conference proceedings
- Japan Society of Civil Engineers, 2009, Journal of Japan Society of Civil Engineers, Ser. H (Engineering Education and Practice), 1, 135 - 143, Japanese
[Refereed]
Scientific journal
- 2009, Journal of Applied Mechanics, Vol.12, 383 - 394, EnglishRationale for coefficient of earth pressure at rest derived from prismatic sand heap
[Refereed]
Scientific journal
- 2009, Proceeding of 6th Regional Symposium on Infrastructure Development, 1, 25, EnglishThe critical state theory applied to porous rock considering the distructuration effects
International conference proceedings
- 2009, Proc. the Asian Pacific Conference for Materials and Mechanics 2009, EnglishStress propagation in semi-infinite planar heap of granular medium possessing self-weight in loose condition
[Refereed]
International conference proceedings
Discontinuity at the vertex of the Sekiguchi-Ohta model causes numerical troubles when associated flow rule is applied because the singularity encountered in the derivatives of yield function. Based on Koiter's associated (low rule, the numerical implementation to accommodate the vertex singularity had been generalized. The set of applied strains had been formulated and defined as the domain of metastability. This study is focused on validity of the domain of metastability by a regularized method. Infinitesimal vicinity adjacent to the vertex is considered to regularize all of plastic flow in outwards normal direction to the yield surface. It was confirmed that the metastable domain of the Sekiguchi-Ohta model is bounded by an elliptical cone in principal strain space.
2009, Theoretical and Applied Mechanics Japan, 57, 89 - 94, English[Refereed]
Scientific journal
- JSCE, 2009, Proc．11th JSCE International Summer Symposium, 161 - 164, EnglishEffect of yield function's form on performance of the backward-Euler stress update algorithm for the original cam-clay model
[Refereed]
International conference proceedings
- 土木学会, 2009, 応用力学論文集, 12, 421 - 428, JapaneseStudy of the stratigraphic architecture resistant for salt damage and the method to purify salty ground
[Refereed]
Scientific journal
It is empirical knowledge that vegetation can influence the behavior of earth structure. It prevents surface failure and erosion due to rain and wind, and contributes to the stability of earth structure. Moreover, it encourages water circulation with transpiration, fixes atmospheric nitrogen and carbon via photosynthesis, and improves the environment. Therefore, surface seeding is purposely performed when an earth structure, such as an embankment or an earth dam, is constructed. Typically, vegetation grows on unsaturated soil. Consequently, a constitutive model for unsaturated soil is needed for understanding the effects of vegetation on the ground. In this study, we focus on the effect of vegetation-induced water uptake. The effect of water uptake due to evapo-transpiration can be regarded as reduction of water content within soil and appropriately represented in simulation studies. The constitutive model proposed by Ohno et al. (2007) is used for the simulation. In this model, the effective degree of saturation is treated as a parameter expressing hardening/softening. Moreover, the 'root element,' where the reduction of water content occurs, is applied to the soil/water coupled analysis with unsaturated soil mechanics. To verify the applicability of this model, the accident in Poland where non-uniform settlement and building damage were caused by water uptake of vegetation was simulated. The results show that water uptake increased suction and induced non-uniform settlement. This method is effective for understanding the effects of vegetation on the ground. © 2009 IOS Press.
2009, Proceedings of the 17th International Conference on Soil Mechanics and Geotechnical Engineering: The Academia and Practice of Geotechnical Engineering, 1, 526 - 529, English[Refereed]
International conference proceedings
- Oct. 2008, Proc. of 12th Int. Conf. of IACMAG, pp.992-997, EnglishTheoretical undrained shear behavior of unsaturated soils
[Refereed]
Scientific journal
- 土木学会, Sep. 2008, 応用力学論文集, 11, 331 - 338, Japanese不飽和土/水連成有限要素解析における空間離散化手法の検討
[Refereed]
Scientific journal
- 土木学会, Sep. 2008, 応用力学論文集, 11, 443 - 450, Japanese植生の吸水作用が地盤の安定性に及ぼす影響
[Refereed]
Scientific journal
- CRC Press, Aug. 2008, Advances in Transportation Geotechnics, 389 - 395, English
[Refereed]
In book
- Jun. 2008, 都市安全研究センター報告, (12), 33 - 42, Japaneseジョグジャカルタ近郊集落における地盤条件の調査報告
Research institution
- Jun. 2008, Proc. the first International Conference on Education and Training in Geo-engineering Sciences, 489 - 492, EnglishIntroduction about the Plan of Course System in Lectures of Japanese Geotechnical Society
[Refereed]
International conference proceedings
- Mar. 2008, 神戸大学都市安全研究センター研究報告, (11), 43 - 50, Japaneseタイ東北部における塩害と地盤変状シミュレータを用いた国際協力の可能性
Research institution
- Dec. 2007, Proc 13th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering, 1097 - 1100, EnglishAnalysis of embankment by nonlinear contractancy description
[Refereed]
International conference proceedings
- Nov. 2007, 建設工学研究所論文報告集, (49), 67 - 76, Japanese膨張性土質材料の過圧密時の摩擦を考慮した弾朔性構成則の改良
Research institution
- Nov. 2007, Proc. International Workshop on Long-term Performance of Smectitic Clays Embedding Canisters with Highly Radioactive Waste, EnglishModelling of compression/swelling behavior of compacted bentonite using constant water-content line and constant degree-of-saturation line
[Refereed]
International conference proceedings
- Oct. 2007, Proc. 1st International Symposium on Geotechnical Safety & Risk, EnglishAn application of performance-based design concept to design of compacted ground
[Refereed]
International conference proceedings
- 土木学会, Sep. 2007, 応用力学論文集, 10, 375 - 382, Japanese植生の吸水作用が地盤に及ぼす効果
[Refereed]
Scientific journal
- May 2007, Proc 16th Southeast Asian Geotechnical Conference, 289 - 296, EnglishInhomogeneous Deformation Developing in a Clay Specimen
[Refereed]
International conference proceedings
- May 2007, Proc. 16th Southeast Asian Geotechnical Conference, 289 - 296, EnglishCoefficient of Earth Pressure at rest derived from the Sekiguchi-Ohta modell
[Refereed]
International conference proceedings
- Apr. 2007, Proc. 3rd Asian Conference on Unsaturated Soils, 347 - 352, EnglishThe salt disaster problem and its mathematical modeling
[Refereed]
International conference proceedings
- Apr. 2007, Proc. of the 3rd Asian Conference on Unsaturated Soils, 359 - 364, EnglishThe influences of evapo-transpiration on the ground
[Refereed]
International conference proceedings
- Non-uniform settlement problem of compacted soil caused by the deformation characteristics of unsaturated soil on wetting
The soil/water-coupled analysis for unsaturated soil mechanics with the finite element method is used to express the behavior of compacted earth structures exposed to rainfall. The constitutive model, which is proposed by Karube et al. (1996, 1997) and modified by Karube and Kawai (2001), is formulated for initial and boundary problems and coded as DACSAR-U (lizuka et al., 2000). A deep fill, which consists of compacted, unsaturated soil, was analyzed with DACSAR-U. Different patterns of rainfall were applied to deep fills in finite element simulations. As a result, non-uniform settlement of deep fill can be calculated and the magnitude of settlement of deep fills is dependent on the amount of collapse, namely, the compression due to the decrease in suction. Moreover, delayed settlement due to rainfall and an accumulation of an irreversible settlement due to cyclic rainfall was observed.
JAPANESE GEOTECHNICAL SOC, Apr. 2007, Soils and Foundations, 47 (2), 195 - 206, English[Refereed]
Scientific journal
- Apr. 2007, Proc. 3rd Asian Conference on Unsaturated Soils, 219 - 233, EnglishA study on yield stress in unsaturated clay
[Refereed]
International conference proceedings
- Mar. 2007, 地盤工学ジャーナル 2007年3月号, 2 (1), 25 - 35, Japanese神戸空港護岸築造工事における沖積粘性土層の挙動とその考察
[Refereed]
Scientific journal
- 2007, Proceedings of the Sri Lankan Geotechnical Society’s First International Conference on Soil & Rock Engineering, EnglishComparison of original and modified cam clay models extended for Ko-consolidated clays
[Refereed]
International conference proceedings
- 2007, First Sri Lankan Geotechnical Society International Conference on Soil and Rock Engineering, EnglishSoil/water coupled F.E. Simulation of field performance of 5 embankments placed on homogeneous clay
[Refereed]
International conference proceedings
- 2007, Journal of Applied Mechanics, JSCE, 10, 971 - 982, Japanese
[Refereed]
Scientific journal
- 2007, International Journal for Numerical and Analytical Methods in Geomechanics, 31, 809 - 833, EnglishNumerical investigation on the failure of normally consolidated clays
[Refereed]
Scientific journal
A new constitutive model of swelling soil material is proposed to evaluate its mechanical characteristics. In the case of the compacted bentonite material, nonlinear behavior appears more dominantly than ordinary clay materials in the consolidation test. The original Cam-clay model cannot describe these characteristics observed in the compacted bentonite materials. Therefore, a new modeling that strain increment consists of linear summation of the swelling component and the elast-plastic component is introduced to describe the nonlinear behavior in the unloading stage. From the result of the simulation of the triaxial compression test, it is demonstrated that the stress pass and the stress and strain relationship are well simulated by the new model.
2007, Structural Engineering/Earthquake Engineering, 24 (2), 102 - 111, English[Refereed]
Scientific journal
- Nov. 2006, TAIPEI2006 International Symposium on New Generation Design Codes for Geotechnical Engineering Practice, EnglishNew trend toward performance-based design in the construction industry
[Refereed]
International conference proceedings
- Oct. 2006, Proc. of 3rd International Workshop on New Frontiers in Computational Geotechnics, 91 - 96, EnglishElasto-plastic constitutive modeling for dilative geomaterials in swelling
[Refereed]
International conference proceedings
- Sep. 2006, 応用力学論文集, 9, 471 - 478, Japanese膨張性土質材料の弾朔性構成則に関する研究
[Refereed]
Scientific journal
- Sep. 2006, 応用力学論文集, 9, 407 - 414, Japanese非線形コントラクタンシー表現を用いた土の弾朔性構成モデル
[Refereed]
Scientific journal
- Soil cantilever reinforced by geosynthetics and pre-stressed steel bars
In this paper, the authors focus on the confining effect brought by geosynthetic-reinforcement. The reinforcement effect is not brought by the geosynthtics itself but mobilized complexly as a composite material consisting of geosynthetics and compacted soils. If the geosynthetics and the compacted soils are unified more tightly, higher reinforcement effect may be expected. Then, in this paper, presented is an experiment, that is, making soil cantilevers with compacted soils wrapped by geosynthetics which are tightly unified by prestressed steel bars. Two types of soil cantilevers were constructed. The soil structures were, first, constructed and wrapped by geosynthetics on the bases of styrene forms and, next, prestressed through the steel bars penetrated from the top surface to the bottom of the geosynthetic-reinforced soil structures. The soil cantilever was formed by melting and removing the styrene forms in order from the edge with monitoring the vertical displacements. It was found that amazing reinforcement effect appears by tightly confining the dilative deformation of compacted soils with the geosynthetics and the prestressed steel bars. The reinforcement effect is numerically investigated. A series of elasto-plastic FE numerical simulation was carried out. The compacted soil was modelled to be elasto-plastic body and the geosynthetics was expressed by the elastic material.
MILLPRESS SCIENCE PUBLISHERS, Sep. 2006, Proc. of 8th International Conference on Geosynthetics (CD-ROM), 1213 - 1218, English[Refereed]
International conference proceedings
- Aug. 2006, International Symposium on Earthquake Engineering & Infrastructure & Building Retrofitting (EE & IBR), EnglishOn the Strategic viewpoints for Mitigation and Reconstruction for the Mid-Java Earthquake Disaster from the Lessons of Disasters in Japan
Scientific journal
- Jun. 2006, 土木学会論文集, No.652/III-51,pp.217-228, Japanese掘削工事における周辺地盤の変形予測手法の検討
[Refereed]
Scientific journal
This paper discusses the volume change characteristics of compacted soil based on oedometer test results. After making specimens with different water contents and under different compaction loads, compression tests are conducted under both saturated and unsaturated conditions. The effects of the compaction conditions on the compression curves are discussed. It is confirmed that the yield stress and the water content are important factors when evaluating a compression curve, while dry density and suction are important factors when evaluating the yield stress. Copyright ASCE 2006.
2006, Geotechnical Special Publication, (147), 837 - 848, English[Refereed]
International conference proceedings
- 土木学会, 2006, 応用力学論文集, 9, 377 - 384, Japanese物質移動を考慮した不飽和土/水連成問題の数理モデルと有限要素解析手法
[Refereed]
Scientific journal
- Dec. 2005, 土木学会論文集, No.806/III-73, 33 - 44, Japanese締固め土の圧縮特性に関する評価手法の検討
[Refereed]
Scientific journal
- Dec. 2005, Proc. of the Fifth Workshop on Safety and Stability of Infrastructures against Environmental Impacts, 192 - 203, EnglishElasto-plastic constitutive model to describe soil contractancy in a wide variety under axi-symmetric stress condition
[Refereed]
International conference proceedings
- Kobe University, Nov. 2005, 建設工学研究所論文報告集, (47), 87 - 100, Japanese軟弱盛土基礎地盤の挙動予測における地盤調査結果の差異の影響
Research institution
- Oct. 2005, 東京工業大学 都市地震工学センター，第96回工学地震学・地震工学談話会，地震工学研究レポート, (No.96), 35 - 46, Japanese地盤動態解析の基礎理論
Research institution
- Sep. 2005, Journal of Applied Mechanics, JSCE, Vol.8, Japanese膨張性を有する緩衝材の弾塑性構成則に関する研究
[Refereed]
Scientific journal
- Sep. 2005, 応用力学論文集, Vol.8, 395 - 402, Japanese膨潤性を有する緩衝材の弾朔性構成モデル化
[Refereed]
Scientific journal
- Jun. 2005, Proc. 11th International Association for Computer Methods and Advances in Geomechanics, 327 - 332, EnglishInfluence of ground improvement on the quality of man-made islands
[Refereed]
International conference proceedings
- May 2005, The International Symposium on Numerical Simulation of Environmental Problems, Journal of the Faculty of Environmental Science and Technology, 203 - 209, EnglishMechanical behavior of partly saturated ground considering the effect of evaporation and transpiration
[Refereed]
International conference proceedings
- CHANGES IN THE INSTANTANEOUS SHEAR MODULUS OF NORMALLY CONSOLIDATED CLAY WITH SHEAR HISTORY
Changes in the instantaneous shear modulus associated with the non-coaxiality of NC clay materials are presented. A series of hollow cylindrical shear tests was performed to measure the changes in the instantaneous shear modulus with shear history. After each normally consolidated clay specimen was compressively sheared until a prescribed shear level, it was continuously torsionally sheared under a constant volume to measure the instantaneous shear modulus. Coaxial constitutive relations, such as these of the conventional Cam-clay type of models, predict that the instantaneous shear modulus obtained, does not change regardless of the compressive shear history. On the contrary, it is known that non-coaxial constitutive relations theoretically bring about changes in the instantaneous shear modulus in relation to the compressive shear history. The test results supported the predictions made by the non-coaxial constitutive models. Finally, the proper formulation for the non-coaxiality between the stress and the incremental plastic strain is discussed.
地盤工学会, 15 Apr. 2005, Journal of the Japanese Geotechnical Society, 45 (2), 135 - 143, English[Refereed]
Scientific journal
- Changes in the instantaneous shear modulus of normally consolidated clay with shear history
Changes in the instantaneous shear modulus associated with the non-coaxiality of NC clay materials are presented. A series of hollow cylindrical shear tests was performed to measure the changes in the instantaneous shear modulus with shear history. After each normally consolidated clay specimen was compressively sheared until a prescribed shear level, it was continuously torsionally sheared under a constant volume to measure the instantaneous shear modulus. Coaxial constitutive relations, such as these of the conventional Cam-clay type of models, predict that the instantaneous shear modulus obtained, does not change regardless of the compressive shear history. On the contrary, it is known that non-coaxial constitutive relations theoretically bring about changes in the instantaneous shear modulus in relation to the compressive shear history. The test results supported the predictions made by the non-coaxial constitutive models. Finally, the proper formulation for the non-coaxiality between the stress and the incremental plastic strain is discussed.
JAPANESE GEOTECHNICAL SOC, Apr. 2005, Soils and Foundations, 45 (2), 135 - 143, English[Refereed]
Scientific journal
- Mar. 2005, 神戸大学都市安全研究センター研究報告, (9), 97 - 109, Japanese河川水位上昇に伴う不飽和堤防盛土内の応力状態の変化予測
Research institution
- Feb. 2005, Proc. of Symposium on Elasto-plasticity, 37 - 46, EnglishThe effect of evapo-transpiration through vegetation on unsaturated ground deformation
[Refereed]
International conference proceedings
- Jan. 2005, in the book of Dislocations, Plasticity, Damage and Metal Forming : Material Response and Multiscale Modeling, Key-note-lecture, Proc. Of PLASTICITY'05 : the 11th International Symposium on Plasticity and its Current Applications, edited by A.S.Khan and A, 265 - 267, EnglishThe non-coaxiality induced by stress rate on the instantaneous shear modulus of clays
[Refereed]
Scientific journal
- Jan. 2005, Plasticity, Damage and Metal Forming : Material Response and Multiscale Modeling, Proc. Of PLASTICITY'05: the 11th International Symposium on Plasticity and its Current Applications, edited by A.S.Khan and A.R.Khoei., 286 - 288, EnglishElasto-plastic constitutive equation to describe re-liquefaction phenomenon
[Refereed]
International conference proceedings
- A simple evaluation method of adjacent ground settlement due to excavation work
The prediction of back-fill settlement due to the excavation work is getting important, particularly in the urban area. The finite element simulation would be a suitable choice to answer it. However, it is less feasible in practice to carry it out because input parameters needed in the F.E. simulation are not sufficiently provided in advance at the stage of design work. In the past, some simple evaluation methods for predicting the back-fill settlement due to excavation works were presented by Peck, Long and Moormann et al. and so on. In this paper, a new method capable for predicting the back-fill settlement at the stage of design work is proposed, taking account of design parameters, i.e. soil parameters, retaining wall parameters and construction sequences. The proposed method is built up based on a lot of monitored records obtained from sites and the numerical results obtained from a series of F.E. simulations for imaginary excavation works. It is designed to be simple and useful at the stage of design work. This method consists of two parts, predictions of the maximum amount of back-fill settlement and the distance from the retaining wall. Finally, some case studies in which the proposed new method was applied to actual excavation sites in Japan are presented.
TAYLOR & FRANCIS LTD, 2005, 5th International Conference on Getechnical Aspects of Underground Construction in Soft Ground, 719 - 723, English[Refereed]
International conference proceedings
This paper presents the modeling of the composite soil-geosynthetic structure and discusses the effect of the reinforcement arising from the confining of the deformation of the soil by geosynthetics. A series of compressive shear tests for compacted sandy soil specimens, wrapped in geosynthetics, is carried out for the purpose of quantitatively examining the effect of the geosynthetic reinforcement arising from the confining of the deformation of compacted soils during shearing. Furthermore, an elasto-plastic modeling for compacted soil and a rational determination procedure for input parameters, needed in the elasto-plastic modeling, are presented. In this paper, the subloading yielding Surface is introduced to the elasto-plastic modeling in order to describe the irreversible deformation characteristics of compacted soil during shearing. Since compacted soil is essentially unsaturated and its mechanical behavior is influenced by the suction working in the compacted soil media, the suction effect is taken into account in estimating of the degree of compaction. Finally, an elasto-plastic finite element simulation is conducted and the geosynthetic-reinforcement effect is presented. (C) 2004 Elsevier Ltd. All rights reserved.
ELSEVIER SCI LTD, Oct. 2004, Journal of Geotextiles and Geomembranes, 22 (5), 329 - 358, English[Refereed]
Scientific journal
There are some constitutive models for unsaturated soil. However, their mathematical structures, particularly for expression of collapse phenomenon, are essentially the same. Therefore, it is possible to unify the constitutive models which were proposed in the past. In this paper, a generalized constitutive model for unsaturated soils is presented. First, we outline existing constitutive models for unsaturated soil and, next, we propose a comprehensive constitutive model for unsaturated soils in terms of the effective stress for unsaturated soils. To this new elasto-plastic model, it is easier to introduce sophisticated methods such as a rotational hardening, a subloading surface and so forth. This model is formulated in the form of incremental general stress and strain relationship and is incorporated into a finite element code, DACSAR-U, for unsaturated soils. The performance of the new constitutive model is demonstrated by comparing with the models proposed by Karube et at and by Honda et al
Japan Society of Civil Engineers, Sep. 2004, Journal of applied mechanics, Vol.7 (No.1), 505 - 513, Japanese[Refereed]
Scientific journal
- Aug. 2004, 地盤工学会 土と基礎, 52 (No.8(Ser.No.559)), 25 - 27, Japanese土構造物の維持補修への構成式の応用
[Refereed]
Scientific journal
- Jun. 2004, GeoAsia2004, invited Lecture at ISSMGT TC9 Sponsored Session, Proceedings of the 3rd Asian regional Conference on Geosynthetics, Seoul Korea, 153 - 172, EnglishThe role of numerical simulation for geosymthetic reinforced soil structures - from laboratory tests to full scale structures -
[Refereed][Invited]
International conference proceedings
- Jun. 2004, Proceedings of the 3rd Asian regional Conference on Geosynthetics, 707 - 714, EnglishModeling of the confining effect due to the geosynthetics wrapping of compacted soil specimen considering suction effect
[Refereed]
International conference proceedings
- 2004, Proc. KU-UW International Symposium #1 on Design Strategy towards Safety and Symbiosis of Urban Space, 81 - 88, EnglishSafety and Symbiosis' form Viewpoint of geomechanics
[Refereed]
International conference proceedings
- The Japanese Geotechnical Society, 2004, Proceedings of the Japan National Conference on Geotechnical Engineering, 39, 259 - 260
柴田(1963)、柴田・軽部(1965)、太田・畠(1971)による一連の研究によって提案された弾塑性構成式(太田・畠モデル)において、土のダイレイタンシー挙動は、間隙比(e)と応力比(q/p')との関係において直線としてモデル化されている。しかし、これまでの研究により、土によっては、その関係が必ずしも直線とならないことがわかっている。本研究では、柴田(1963)、柴田・軽部(1965)、太田・畠(1971)による一連の研究を踏襲しながら、より適用性の高いダイレイタンシーの表現式を提案することで、新しい土の弾塑性構成式を導出している。
The Japanese Geotechnical Society, 2004, Proceedings of the Japan National Conference on Geotechnical Engineering, 39, 261 - 262これまで,土構造物の挙動予測を行う際に関口・太田による弾(粘)塑性構成モデルが組み込まれた二次元土/水連成弾(粘)塑性有限要素解析プログラム(DACSAR)が多く用いられてきた.しかし,現行のDACSARで適用されている負荷判定法は粘塑性体積ひずみと定める閾値の大小関係で行われているため,閾値の定め方によって負荷判定結果が左右される.そこで,本報告は飯塚らが提案した閾値を必要としない負荷判定法をDACSARに組み込み,K0圧密および静的非排水繰返しせん断の解析結果を比較することにより,新しく提案した負荷判定法の適用性について検討したものである.
The Japanese Geotechnical Society, 2004, Proceedings of the Japan National Conference on Geotechnical Engineering, 39, 913 - 914- Dec. 2003, Proc. 13th Regional Conference for Africa, The Involvement of Geotechnical Engineering in Infrastructure development in Africa, 713 - 719, EnglishConstitutive parameters of compacted sandy soils
[Refereed]
International conference proceedings
- Oct. 2003, Proc. of the International Workshop on Prediction and Simulation Methods in Geomechanics (IWS-Athens 2003), 21 - 24, EnglishThe change of instantaneous shear modulus associated with non-coaxiality of normally consolidated clays
[Refereed]
International conference proceedings
- Deformation analysis of soft subsoil on sloping bedrock loaded by highway embankment with stabilization methods
A highway embankment built in Akita prefecture using ground stabilization methods was constructed on very soft peat and clay deposits on a sloping base. This paper presents a case study of a soil/water coupled elasto-viscoplastic finite element simulation of an actual embankment construction, that is, the deformation analysis of a soft clayey foundation deposited on an inclined base with embankment loading. For execution of the numerical simulation, determining the input parameters needed in the analysis and evaluating the shape of sloping bedrock under the ground were problems. The former is discussed for a practical procedure of determining input parameters using unconfined compression strengths and the latter is accomplished by drawing a contour map of the top face of the bedrock under the ground, with reference to the geographical features of the area around the site and to a topographic map. The performance of the numerical simulation is discussed in comparison with in-situ monitored records. The effectiveness of ground stabilization methods employed at the site is also a topic of discussion.
JAPANESE GEOTECHNICAL SOC, Oct. 2003, Soils and Foundations, 43 (5), 81 - 92, English[Refereed]
Scientific journal
- 土木学会, Sep. 2003, 応用力学論文集, 6, 1131 - 1139, Japanese施工履歴の違いを考慮したCAES地下空洞掘削シミュレーション
[Refereed]
Scientific journal
- Sep. 2003, Proc. International Workshop on Geotechnics of Soft Soils, pp.49-62, English15 years continuous settlement of a highway embankment on very soft clay
[Refereed]
International conference proceedings
- Aug. 2003, Proc. JSPS Core University Program on Environmental Engineering Symposium, 391 - 408, EnglishUndrained strength measured in lab/in-situ tests and strength mobilized at failure in the field
[Refereed]
International conference proceedings
- Aug. 2003, Proc. of JSPS Core University Program on Environmental Engineering Symposium, 381 - 390, EnglishSoil/water coupled response to repeated loading
[Refereed]
International conference proceedings
- Aug. 2003, Proc. of 13th European Conference on Soil Mechanics and Geotechnical Engineering, 1, 709 - 712, EnglishNumerical assessment of long term non-uniform settlement of man-made island
[Refereed]
International conference proceedings
- Aug. 2003, Proc. of 13th European Conference on Soil Mechanics and Geotechnical Engineering, 1, 735 - 738, EnglishInfluence of water level change on the behavior of unsaturated zone
[Refereed]
International conference proceedings
- Numerical interpretation of a shape of yield surface obtained from stress probe tests
Experimental evidence suggests that a mutual relationship between anisotropy and structure of clays exists. It was hypothesized that development and decay of the structure of clays (called structuralizing and destructuralizing) can be regarded as development of anisotropy and decay of anisotropy (isotropization), respectively. Using this hypothesis, an anisotropic rotational hardening rule was incorporated in the Sekiguchi-Ohta elasto-plastic constitutive model. The subloading surface concept was also introduced to model the plastic deformation inside the yield surface more accurately. The proposed model provided some rational as well as physical explanations for the experimental facts. Using the proposed model, it was possible to simulate the apparent softening behavior observed in anisotropically consolidated specimens. For isotropically consolidated specimens, no softening was observed, which is consistent with the experimental data. At the critical state, the undrained shear strength of the anisotropically consolidated specimens was the same as that of the isotropically consolidated specimens. This is due to both specimens having the same soil structure after large shearing. The shape of yield surface obtained from stress probe tests was investigated by simulating the tests with the proposed model. Typical data of the stress probe tests of natural clays shows that the yield surface generally has a smooth elliptical shape. By modeling the rotation of yield surface, the proposed model was capable of simulating this 'apparent' yield surface.
JAPANESE GEOTECHNICAL SOC, Jun. 2003, Soils and Foundations, 43 (3), 95 - 104, English[Refereed]
Scientific journal
- Apr. 2003, Proc. of 2nd Asian Conference on Unsaturated Soils, 171 - 176, EnglishThe deformation and the moisture characteristics of unsaturated soils under isotropic loading and undrained condition
[Refereed]
International conference proceedings
- Apr. 2003, Proc. of 2nd Asian Conference on Unsaturated Soils, 429 - 434, EnglishSuction change of compacted soils during static compaction test
[Refereed]
International conference proceedings
- Apr. 2003, Proc. of 2nd Asian Conference on Unsaturated Soils, 271 - 276, EnglishEstimation of the consolidated yielding stress of compacted soil considering the effects of suction
[Refereed]
International conference proceedings
- Apr. 2003, Proc. of 2nd Asian Conference on Unsaturated Soils, 299 - 304, EnglishComputational soil/water coupled unsaturated soil behavior
[Refereed]
International conference proceedings
- Apr. 2003, Proc. of 2nd Asian Conference on Unsaturated Soils, 177 - 180, EnglishA study of the relation between volume change characteristics of compacted soil and the condition of compaction
[Refereed]
International conference proceedings
- Jan. 2003, Soft Ground Engineering in Coastal Areas, 397 - 407, English
[Refereed]
In book
本研究の目的は,室内試験を境界値問題と捉え,正規圧密粘土の非排水三軸圧縮・伸張試験,平面ひずみ圧縮試験をシミュレーションし,供試体の破壊挙動を解析的に検討することである.計算を行う道具として,有限変形弾塑性理論に基づく土/水連成3次元有限要素プログラムを開発した.シミュレーションにはMises型のCam-clayモデルを用いているため,解析解として得られる破壊強度に圧縮側,伸張側あるいはその中間で違いがあれば,一般に実験で得られるMohr-Coulombの規準は粘土の材料としての性質ではなく,他の要因に起因するものと考えられる.
The Japanese Geotechnical Society, 2003, Proceedings of the Japan National Conference on Geotechnical Engineering, 38, 293 - 294既存のモデルでは,構造・過圧密の変化を表す概念として上・下負荷面モデル,異方性の変化を表す概念として回転硬化則を用いていたが,両者の関係に関しては十分な議論がなされていなかった.本研究では,構造の劣化と異方性の変化には不可分な関係があると考え,関口・太田モデルに上・下負荷面の概念と回転硬化則を導入し,構造・過圧密・異方性の変化を統一的に取扱える構成モデルを開発した.具体的には,回転硬化の発展則を上負荷面の発展則の関数で表すことによって,構造と異方性を結びつけた.開発した構成モデルを用いて,構造を持った土の各種室内力学試験を解析し,これまで表すことができなかった実験事実を説明し,妥当性を示した.
The Japanese Geotechnical Society, 2003, Proceedings of the Japan National Conference on Geotechnical Engineering, 38, 283 - 284- Oct. 2002, roc. of 4th International Symposium on Geotechnical Aspects of Underground Construction in Soft Ground, IS-Toulouse, EnglishMechanical influence of a large-scale excavation on the adjacent embankment
[Refereed]
International conference proceedings
- Japan Society of Civil Engineers, Sep. 2002, 応用力学論文集, 5, 785 - 792, Japanese
[Refereed]
Scientific journal
- Sep. 2002, 施工過程を考慮した地盤の変形・破壊予測に関するシンポジウム発表論文集, 17 - 24, Japanese地盤沈下の予測理論と実際
[Refereed]
Symposium
The mechanical behavior of unsaturated soils strongly depends on the pore water distribution as well as the suction. The water characteristic curve (W. C. C) specifying the pore water content and the suction value plays a very important role in describing the mechanical modeling for unsaturated soils. However, the W. R. 0 shows the hysteresis loop in the wetting/drying processes. This paper emphasizes the importance of considering the hysteresis of W.C.C in the modeling. The accumulation of irreversible strains in the soil structures caused by rainfalls cannot be explained well without considering the hysteresis of W. C. C. An existing model of W. C. C is modified so as to express the accumulation of irreversible strains as the cyclic suction loading. Finally, it is shown that the modified model well explains the experimental results.
Japan Society of Civil Engineers, Sep. 2002, 応用力学論文集, 5, 777 - 784, Japanese[Refereed]
Scientific journal
- 土木学会, Sep. 2002, 応用力学論文集, 5, 767 - 776, Japanese施工履歴の違いを考慮した人工島の品質評価に対する検討
[Refereed]
Scientific journal
- Sep. 2002, Proc of 7th International Conference on Geosynthetics, 1133 - 1136, EnglishCompressive shear tests of compacted soils wrapped by geosynthetics
[Refereed]
International conference proceedings
- Sep. 2002, Proc of 7th International Conference on Geosynthetics, 307 - 312, EnglishA series of trial embankments of reinforced earth
[Refereed]
International conference proceedings
- Aug. 2002, 土と基礎, Vol.50 (No.8 (Ser.No.535)), 6 - 8, Japanese地盤沈下の予測理論と実際 －施工に伴う荷重や変位の履歴による地盤応答－
[Refereed]
Scientific journal
- Jul. 2002, 土と基礎, Vol.50 (No.7 (Ser.No.534)), 28 - 30, Japanese開削トンネル設計時における周辺地盤の簡易沈下予測
[Refereed]
Scientific journal
- Apr. 2002, Journal of Structural Engineering, Vol.48A (1), 185 - 194, EnglishFEM formulation for analysis of soil constitutive model with a corner on the yield surface
[Refereed]
Scientific journal
- 神戸大学都市安全研究センター, Mar. 2002, 神戸大学都市安全研究センター研究報告, (6), 397 - 408, Japanese
Research institution
- Japan Society of Civil Engineers, 2002, Journal of applied mechanics, 5, 601 - 610, Japanese
[Refereed]
Scientific journal
- The Japanese Geotechnical Society, 2002, Proceedings of the Japan National Conference on Geotechnical Engineering, 37, 761 - 762, English
- The Japanese Geotechnical Society, 2002, Proceedings of the Japan National Conference on Geotechnical Engineering, 37, 327 - 328
- The Japanese Geotechnical Society, 2002, Proceedings of the Japan National Conference on Geotechnical Engineering, 37, 325 - 326
- Dec. 2001, Journal of Geotechnical Engineering, Vol.32 (No.3), 153 - 164, EnglishGeological approach to the void ratio distribution for aged clays based on Bjerrum's hypothesis
[Refereed]
Scientific journal
- Applicability of an elasto-plastic model for reinforced soil structures
The reinforcement technique using flexible materials such as geosynthetics has been widely employed in the current engineering practice. However, the reinforcement mechanism has not revealed sufficiently, i.e. the mechanical interaction between the reinforcements and soils, the confining effect induced by reinforcements and so forth, and then it has not yet led into a proposal of rational design procedure. This paper reports in-situ loading tests carried out on the compacted soil structure reinforced by flexible beltlike materials. Elasto-plastic finite element simulations were also performed considering dilatancy characteristics of compacted soils during shearing. Throughout comparison with the field records monitored in the site and the results obtained from the conventional elastic computation, discussed are the applicability of the elasto-plastic analysis and the role of dilatancy characteristics of compacted soils in the reinforcement mechanism.
A A BALKEMA PUBLISHERS, Nov. 2001, Proc. of the International Symposium on Landmarks in Earth Reinforcement (IS-Kyushu 2001), Vol.1, 507 - 510, English[Refereed]
International conference proceedings
- Oct. 2001, 応用力学論文集, Vol.4, 367 - 374, Japanese体積変化を考慮したせん断帯生成理論
[Refereed]
Scientific journal
- Oct. 2001, 応用力学論文集, Vol.4, 285 - 294, Japaneseセルフボーリングプレッシャーメータから得られる強度に間隙水の移動が及ぼす影響
[Refereed]
Scientific journal
- Oct. 2001, Journal of Applied Mechanics, Vol.4, 295 - 306, EnglishNonlinear analysis for stress-strain-strength of clays using return-mapping algorithms
[Refereed]
Scientific journal
- Aug. 2001, Proc. 3rd Int. Summer Symposium, 201 - 204, EnglishIntegration algorithms for soil constitutive equations with a singular hardening vertex
[Refereed]
International conference proceedings
- Jun. 2001, 土木学会論文集, (No.680/III-55), 15 - 28, Japaneseジオシンセティックスによるダイレイタンシー拘束効果
[Refereed]
Scientific journal
- Japan Society of Civil Engineers, 2001, Doboku Gakkai Ronbunshu, (694), 67 - 79, Japanese
[Refereed]
Scientific journal
- 2001, 第51回理論応用力学講演会講演論文集, 51 (0), 91 - 91, Japanese
[Refereed]
Scientific journal
- Nov. 2000, Proc. of 3rd Regional Symposium on Infrastructure Development in Civil Engineering, 373 - 380, EnglishA repair work of a bridge abutment suffering from excessive deformation of soft clay foundation
[Refereed]
International conference proceedings
- 土木学会, Sep. 2000, 土木学会論文集, (No.659/III-52), 153 - 164, Japanese不飽和土の応力－ひずみ関係式
[Refereed]
Scientific journal
- 土木学会, Sep. 2000, 土木学会論文集, (No.659/III-52), 165 - 178, Japanese間隙水分布の違いを考慮した不飽和土／水連成解析
[Refereed]
Scientific journal
- Effects of some parameters on braced-excavation of soft clay by numerical studies
Apart from following general outlines for input procedures and parameter findings when performing excavation analysis using FEM, some additional considerations should be taken. The influences of appropriate soil stiffness, pre-load efficiency, actual strut stiffness, soil/wall interface, crack in concrete retaining wall, and foundation piles installed before excavation have been investigated to weight the impact on analysis quality, enhancing acceptability in practice. Computed deformations and strut axial loads of a case study agreed quite well with field responses after applying these effects.
A A BALKEMA PUBLISHERS, Sep. 2000, Proc. of Coastal Geotechnical Engineering in Practice (IS-Yokohama), Vol.1, 351 - 356, English[Refereed]
International conference proceedings
- Aug. 2000, 鉄道総合技術論文誌鉄道総研報告, 14 (8), 25 - 30, Japanese開削工事における周辺地盤変形要因に関する解析的研究
Research institution
The prediction of back-fill settlement due to the excavation work is getting important, particularly in the urban area. The finite element simulation would be a suitable choice to answer it. However, it is not feasible in practice to carry it out because input parameters needed in the F. E. simulation are not provided in advance in the stage of design work. This paper proposes a simple prediction method of the back-fill settlement due to the excavation work. The proposed method is built based on a lot of monitored data obtained from sites and the numerical results obtained from a series of F. E. simulations for imaginary excavation sites. It is designed to be simple and useful in the stage of design work. This method consists of two parts, prediction of the maximum amount of back-fill settlement and prospect of the distance from the retaining wall.
Japan Society of Civil Engineers, 21 Jun. 2000, Doboku Gakkai Ronbunshu, 652, 217 - 227, Japanese- Jun. 2000, 土木学会論文集, (No.652/III-51), 217 - 228, Japanese掘削工事における周辺地盤の変形予測手法の検討
[Refereed]
Scientific journal
- Apr. 2000, 神戸大学大学院自然科学研究科紀要, 18-B, 51 - 59, Japanese締固め土の圧縮挙動に関する弾朔性構成モデルの適用
Research institution
- Mar. 2000, 土木学会論文集, (,No.645/III-50), 209 - 221, Japanese道路盛土の除去およびEPS置換に伴う軟弱地盤の挙動解析
[Refereed]
Scientific journal
- Shear strength mobilization in shear box test under constant volume
The specification of strength parameters is an important task in the design work of slope stability. Usually laboratory shear tests are employed to determine the strength parameters. The specimen in the laboratory tests is intended and generally assumed to represent a single point in the in-situ soil medium. And, the strength parameters obtained are interpreted as material properties of the soil element. However, since the uniformity of stress/strain distribution within the specimen is hardly achieved during shearing, the strength parameters thus obtained cannot be essentially regarded as material properties. In this paper, the shear box test under the condition of constant volume is considered and the distribution of stress/strain within the specimen is rigorously examined through numerical simulations based on finite incremental deformation theory. The mobilization of strength is explained associated with the development of shear bands in the specimen during shear.
A A BALKEMA PUBLISHERS, Nov. 1999, Proc. of International Symposium on Slope Stability Engineering, Geotechnical and Geoenvironmental Aspects (IS-Shikoku), 763 - 768, English[Refereed]
International conference proceedings
- Sep. 1999, 土木学会論文集, No.631/III-48, 179 - 192, Japaneseダイレタンシーを考慮したジオシンセティックス補強盛土有限要素解析
[Refereed]
Scientific journal
- Jul. 1999, 土と基礎, Vol.47-9 (No.498), 13 - 16, Japanese土留め掘削周辺地盤の挙動と三次元解析事例
[Refereed]
Scientific journal
- May 1999, 土と基礎, Vol.47 (No.5), 21 - 24, Japanese粘土供試体の圧縮せん断破壊－観察とシミュレーション－
[Refereed]
Scientific journal
- Mar. 1999, 土木学会論文集, No.617/III-46, 1 - 18, Japanese正規粘土供試体せん断時における局所変形の遷移
[Refereed]
Scientific journal
- Dilatancy localization in clay specimen under shearing
The strain localization developing inside clay specimens during shear is examined through the experimental observation and numerical F.E. simulation. In the experiment, clay specimens of column and hollow-cylinder shapes are uniaxially sheared and the development of shear bands is observed. The numerical simulation of compression shear is carried out under the plane strain condition for normally consolidated clay specimens with impermeable boundaries by using the elasto-plastic soil/water coupled finite element computation technique based on the finite deformation theory. Although the geometric boundary conditions are different in the experiment and simulation, discussed are the development of shear bands on/in the specimen and the transition of the localization mode which are found commonly in the experiment and simulation.
A A BALKEMA PUBLISHERS, Nov. 1998, Proc. of 4th International Workshop on Localization and Bifurcation Theory for Soils and Rocks, 345 - 354, English[Refereed]
International conference proceedings
- Interpretation of in-situ and laboratory tests on soft clays
Mechanical properties of soft clays, such as deformability and strength, are estimated using data obtained from in-situ and laboratory tests. These test methods were developed through experience gained in the development of geotechnical engineering. The undrained strength, for instance, of a soft clay estimated by using any one of these in-situ or laboratory tests is not usually the same as that estimated by another one of these tests. There are many possible reasons for the apparently different response of the clay to each of these testing methods. The differences caused by factors such as disturbance, stress history, detailed testing procedures, are sometimes surprisingly influential. This paper shows examples of the above mentioned complications encountered in engineering practice. The paper also describes the interpretation of such complications by means of an elasto-plastic constitutive model which was proposed by Sekiguchi and Ohta in 1977.
A A BALKEMA PUBLISHERS, Apr. 1998, Proc. of 1st International Conference on Site Characterization, Vol.1, 403 - 408, English[Refereed]
International conference proceedings
- Evaluation of undrained strengths obtained from three shear tests
This paper presents evaluation of undrained strengths obtained from unconfined compression tests, constant volume shear box tests and field vane shear tests which were carried out in a site. Theoretical expressions of these undrained strengths derived from the elasto-plastic constitutive model are summarized. And discussed are the correction factors that help converting the undrained strengths obtained from tests to ideal undrained strengths comparable to the theoretical strengths. Throughout comparison of the measured strengths and the theoretical predictions, reliable specification of the constitutive parameters for the model from the measured strengths is examined.
A A BALKEMA PUBLISHERS, Apr. 1998, Proc. of 1st International Conference on Site Characterization, Vol.2, 1265 - 1271, English[Refereed]
International conference proceedings
- Mar. 1998, Proc. of 6th International Conference on Geosynthetics, Vol.2, 551 - 556, EnglishApplication of dilatancy models to soils reinforced by geosynthetics
[Refereed]
International conference proceedings
- Dec. 1997, 土木学会論文集, No.582/III-41, 173 - 182, Japanese粘性土の等体積一面せん断強さ
[Refereed]
Scientific journal
- Sep. 1997, 土木学会論文集, No.575/III-40, 207 - 217, Japanese土/水連成有限要素解析に基づいた限界盛土高さ推定法
[Refereed]
Scientific journal
- Seismic deamplifying effect of soft clay layers
The seismic deamplifying effect of soft clay layers is described. This deamplifying effect of soft clay layers on the propagated waves due to an earthquake is significantly influenced by the degree of consolidation of the soft clay underlying the site. In this paper, two buildings on Rokko Island are analysed. First, the static soil/water coupled analyses are carried out to assess the initial equilibrium conditions of the site just before the earthquake and, secondly, the dynamic response analyses are performed based on the data obtained from the static analyses. The emphasis is placed on evaluating the factor of safety against liquefaction at the various stages of consolidation and at the completion of consolidation. The results seem to be consistent with the overall phenomena observed in Port island and Rokko Island.
A A BALKEMA PUBLISHERS, Jul. 1997, Proc. of 14th International Conference on Soil Mechanics and Foundation Engineering (ICSMFE), Vol.2, 859 - 862, English[Refereed]
International conference proceedings
- Apr. 1997, 地盤工学における逆解析の適用と施工管理に関するシンポジウム論文集, 123 - 132, Japanese軟弱地盤上に施工された高速道路盛土による変形とその数値シミュレーション
[Refereed]
Symposium
- Apr. 1997, 地盤工学における逆解析の適用と施工管理に関するシンポジウム論文集, 145 - 150, Japaneseジオシンセティックスで補強された盛土構造物の変形挙動
[Refereed]
Symposium
- Feb. 1997, 土と基礎, (2), 11 - 14, Japanese沈下予測解析における基準と初期条件の重要性
[Refereed]
Scientific journal
- Numerical simulation of beam-shaped soil structure reinforced by geosynthetics
A full-scale model test was conducted to investigate the mechanism of soil reinforcement by geosynthetic materials, A beam shaped soil structure reinforced by geosynthetics was designed and the global momentum stiffness was examined. This paper presents a brief description of the theoretical estimate of the global momentum stiffness of the reinforced structure for the laboratory model test and the numerical simulation of the full scale model test. The numerical simulation and the field test indicate that the effect of soil confinement by the geosynthetic material was particularly significant. A comparison of the numerical and field results is also presented.
A A BALKEMA, Nov. 1996, Proc. of International Symposium on Earth Reinforcement (IS-Kyushu), Vol.1, 255 - 260, English[Refereed]
International conference proceedings
- Nov. 1995, 第40回地盤工学シンポジウム論文集, 331 - 338, Japanese梁形状のジオシンセティックス補強土構造物の力学挙動
[Refereed]
Symposium
- Nov. 1995, 第40回地盤工学シンポジウム論文集, 237 - 242, Japanese間隙水の移動を考慮した極限解析
[Refereed]
Symposium
- Jun. 1995, 土木学会論文集, No.517,III-31, 209 - 215, Japanese“自然堆積粘土に対するベーンせん断試験結果の解釈”に対する討議回答
[Refereed]
Scientific journal
- Feb. 1995, 直接型せん断試験の方法と適用に関するシンポジウム論文集, 147 - 154, Japanese一面せん断試験の力学的意義と結果の解釈
[Refereed]
Symposium
- 1995, 岩の力学'95(岩の力学連合会、東京), 1022 - 1025, Japanese都市型CAESタンクの周辺軟岩安定性に関する数値解析－関口・太田の弾粘塑性モデルによる予備的考察－
[Refereed]
Symposium
- A A BALKEMA, 1995, Proc. of International Symposium on Compression and Co nsolidation of Clayey Soils (IS-Hiroshima), Vol.1, 189 - 194, EnglishPore water migration during plane strain triaxial test
[Refereed]
International conference proceedings
- Dec. 1994, Proc. of International Conference on Computational Methods in Structure and Geotechnical Engineering, Vol.4, 1516 - 1520, EnglishNon-linear soil/water coupled formulation and choice of element type used in deformation/stability analysis
[Refereed]
International conference proceedings
- Nov. 1994, 第39回土質工学シンポジウム論文集, 187 - 194, Japanese海成粘土の一面せん断特性と一軸圧縮強度・ベーン強度の力学的関連性
[Refereed]
Symposium
- Oct. 1994, 地盤の破壊とひずみの局所化に関するシンポジウム論文集, 181 - 188, Japanese破壊近傍での有限要素の特性変化
[Refereed]
Symposium
- Oct. 1994, 地盤の破壊とひずみの局所化に関するシンポジウム論文集, 135 - 142, Japanese粘性土の弾朔性構成式の一表現
[Refereed]
Symposium
- Jul. 1994, 構造工学における数値解析法シンポジウム論文集, 18, 33 - 38, Japanese3次元土／水連成FEMにおける種々の離散化と計算精度・効率
[Refereed]
Symposium
- Mar. 1994, 土木学会論文集, No.487/III-26, 227 - 236, Japanese粘土地盤におけるベーンせん断強度の発現メカニズム
[Refereed]
Scientific journal
- A A BALKEMA PUBLISHERS, Jan. 1994, Proc. of 13th International Conference on Soil Mechanics and Foundation Engineering (ICSMFE), Vol.2, 751 - 754, EnglishProgressive failure of soft clay under embankment
[Refereed]
International conference proceedings
- Dec. 1993, 土木学会論文集, No.481/III-25, 145 - 154, Japanese自然堆積粘土に対するベーンせん断試験結果の解釈
[Refereed]
Scientific journal
- Mar. 1993, 金沢大学工学部紀要, 27 - 33, Japaneseハダカ中空円筒供試体によるKo圧密非排水せん断試験装置
Research institution
- Mar. 1993, 金沢大学工学部紀要, 第26巻(通巻第65号), 19 - 26, Japaneseジオテキスタイルで補強された複合地盤の曲げ剛性
Research institution
- THOMAS TELFORD SERVICES LTD, Jul. 1992, Proc. of C.P.Wroth Memorial Symposium: Predictive soil mechanics, 387 - 405, EnglishUse of field vane test data in analysis of soft clay foundation
[Refereed]
International conference proceedings
- The effect of stress induced anisotropy on shear band formation
This paper describes the effect of non-coaxiality arising from material anisotropy on bifurcation phenomena such as shear band formation. The elasto-plastic model originally proposed by Sekiguchi and Ohta [7] is one of the typical models which include anisotropy and it is used to examine the effect of anisotropy on shear band formation. First, we shall extend this elasto-plastic model for infinitesimal strain to a model for finite strain and discuss the mathematical structure of this model. The stress induced anisotropy is found to bring about a vertex-like effect, such as the non-coaxiality between the Cauchy stress tensor and a plastic stretching tensor, into the constitutive relation. Then, we shall examine the effect of this non-coaxiality on bifurcation conditions in relation to the material rigidity which changes with the angle of simple shear. Finally, it will be concluded that this non-coaxiality arising from the anisotropy does not contribute much to triggering instability by localization of the deformations which result in shear band formation, while on the other hand, the non-coaxiality due to the yield vertex effect is rather inclined towards instability by localization of the deformations.
SPRINGER VERLAG, Mar. 1992, Archive of Applied Mechanics, 62, 104 - 114, English[Refereed]
Scientific journal
- May 1991, Proc. of International Conference on Computer Methods and Advances in Geomechanics, Vol.2, 1165 - 1170, EnglishAnalysis of post peak behaviour of foundations
[Refereed]
International conference proceedings
- A A BALKEMA, May 1991, Proc. of International Conference on Computer Methods and Advances in Geomechanics, Vol.1, 273 - 278, EnglishDesign strength Su derived from pressuremeter tests
[Refereed]
International conference proceedings
- A A BALKEMA, May 1991, Proc. of International Conference on Computer Methods and Advances in Geomechanics, Vol.2, 1017 - 1022, EnglishDeformation analysis of anisotropically consolidated clay foundation loaded by 5 embankments
[Refereed]
International conference proceedings
- A A BALKEMA, May 1991, Proc. of International Conference on Computer Methods and Advances in Geomechanics, Vol.2, 1191 - 1196, English3-D analysis of soil/water coupling problems using elasto-viscoplastic constitutive relationship
[Refereed]
International conference proceedings
- Nov. 1990, 第35回土質工学シンポジウム論文集, 39 - 46, Japaneseひずみ軟化を示す地盤挙動の有限要素解析
[Refereed]
Symposium
- Aug. 1990, Proc. of 11th International Conference of the Terrian-Vehicle Systems, 1123 - 1128, EnglishStrength of compacted earth fill
[Refereed]
International conference proceedings
- THOMAS TELFORD SERVICES LTD, Apr. 1990, Proc. of 3rd International Conference on Pressuremeters, 189 - 198, EnglishEffects of drainage on interpretation of pressuremeter tests in clay
[Refereed]
International conference proceedings
- Dec. 1989, Soils and Foundations, Vol.29 (No.4), 1 - 13, EnglishShear bands formation numerically simulated by a non-coaxial Cam-clay model
[Refereed]
Scientific journal
- Nov. 1989, 第34回土質工学シンポジウム論文集, pp.233-240, 233 - 240, Japanese平面ひずみ試験におけるせん断帯生成シミュレーション
[Refereed]
Symposium
- Nov. 1989, 第34回土質工学シンポジウム論文集, 287 - 294, Japanese大深度竪坑の掘削シミュレーションと施工上の問題点
[Refereed]
Symposium
- Nov. 1989, 第34回土質工学シンポジウム論文集, 225 - 232, Japaneseせん断（すべり線）の生成機構と応力誘導異方性
[Refereed]
Symposium
- Sep. 1989, Soils and Foundations, Vol.29 (No.3), 41 - 53, EnglishGeneral theory of shear bands formation by a non-coaxial Cam-clay model
[Refereed]
Scientific journal
- May 1989, 土と基礎, Vol.37 (No5), 47 - 52, Japanese種々の掘削工法を検討できる山留め計算法
[Refereed]
Scientific journal
- Mar. 1989, サンプリングシンポジウム論文集, 35 - 40, Japanese不撹乱試料の残留有効応力と１軸圧縮強度
[Refereed]
Symposium
- A A BALKEMA, 1989, Proc. of 12th International Conference on Soil Mechanics and Foundation Engineering (ICSMFE), Vol.1, 71 - 74, EnglishUNCONFINED COMPRESSION STRENGTH OF SOFT AGED CLAYS
[Refereed]
International conference proceedings
- Apr. 1988, Proc. of 6th International Conference on Numerical Methods in Geomechanics, Vol.1, 299 - 304, EnglishCoupled elasto-plastic deformation-flow finite element analysis using imaginary viscosity procedure
[Refereed]
International conference proceedings
- Apr. 1988, Proc. of 6th International Conference on Numerical Methods in Geomechanics, Vol.3, 2043 - 2050, EnglishSoil-structure interaction related to actual construction sequences
[Refereed]
International conference proceedings
- Dec. 1987, 土木学会論文集, No.388/III-8, 121 - 130, Japanese仮想粘性法による弾塑性変形・浸透流連成解析
[Refereed]
Scientific journal
- Elsevier BV, Sep. 1987, Soils and Foundations, 27 (3), 71 - 87, English
[Refereed]
Scientific journal
- Jun. 1987, 土木学会論文集, No.382/III-7, 255 - 263, Japanese極限支持力と地盤内応力変化の有限要素解析
[Refereed]
Scientific journal
- Feb. 1972, 土と基礎, No.2,pp.11-14, Japanese沈下予測解析における基準と初期条件の重要性
[Refereed]
Scientific journal
MISC
- 九州橋梁・構造工学研究会, Dec. 2020, 土木構造・材料論文集, (36), 15 - 19, Japanese都市デジタルツインによる防災減災パラダイムシフト
Introduction scientific journal
- Dec. 2020, 原子力バックエンド研究, 27 (2), 115 - 118, Japanese高レベル放射性廃棄物地層処分における性能設計
Introduction scientific journal
- 21 Sep. 2020, 神戸新聞, Japanese【神戸大学コラム 安心の素】災害リスク 定量化の試み
Others
- 公益財団法人高速道路調査会, Sep. 2020, 高速道路と自動車, 63 (9), 9 - 10, Japaneseベイス推定を用いた災害即時の被害予測による応急対応タイムラインの実効性の向上
Introduction other
- Jun. 2020, IPA News Letter, 5, 5 - 8, JapaneseParadigm shift of disaster prevention and mitigation by city scale simulation, Special Contribution
Introduction scientific journal
- Jan. 2020, 土木学会誌, 105 (1), 36 - 39, Japanese受け身の「受注」から課題解決型の「提案」へ － 都市丸ごとシミュレーション技術の活用 －
Introduction scientific journal
- 2020, 神戸大学暁木会ニュース, Vol.41, Japanese研究報告（都市丸ごとのシミュレーション技術研究組合）
Others
- Sep. 2019, 地盤工学会誌, 67 (No.9、Ser。No.740), 28 - 31, Japanese報告，不飽和土の圧縮特性と締固め曲線との関連性
Introduction scientific journal
- 05 Aug. 2019, JACIC情報, 120, 9 - 13, JapanesePart 1特別寄稿 「神戸モデル」の社会実装 －３次元都市丸ごとのシミュレーション技術による防災・減災パラダイムシフト－
Introduction other
- Jun. 2017, 西松建設技報(CD-ROM), 40, Japanese地層処分における緩衝材の再冠水挙動に関する解析的検討
- 2016, 地盤工学会誌，10月号, 64 (10), 6 - 9, Japanese論説 実務における数値解析技術の国際展開
Introduction scientific journal
- 2016, 前田建設技術研究所報, Vol.57, 14 - 14, Japanese土の骨格構造の発達・劣化を考慮した弾・粘塑性構成モデルの検討
- 理工図書, Mar. 2015, 土木技術3月号, Vol.70 (No.3), 8 - 13, Japanese性能設計化地層処分技術への期待
Introduction other
- 中央復建コンサルタンツ, Apr. 2014, 中央復建コンサルタンツ広報誌, 3 - 4, Japanese防災・減災に対する国土強靭化
Others
- 2014, 自由民主党機関紙「自由民主」連載記事, Japanese超広域・複合災害に備える：第1回南海トラフ地震（平成26年2月18日，3面），第2回科学的知見による被害想定（平成26年2月25日，6面），第3回レジリエントな国土強靭化（平成26年3月4日，6面），第4回専門的知見の総結集（平成26年3月11日，6面）
Others
- 2013, 地盤工学会誌, Vol.62 (No.2), 16 - 19, Japanese津波堆積物とその特性 (< 特集> 汚染土壌・廃棄物等の処理)
Introduction scientific journal
After the Great East Japan Earthquake occurred on 11 March 2011, many earthquake-induced damages of levees and reclaimed lands were reported. According to the investigation to the failure characteristic of levees summarized by Tohoku Regional Development Bureau of MLIT, damages caused by liquefaction of foundation ground would involve basal settlement and saturated condition of loosening construction materials inside levees submerged under water. This study aims to highlight that initial stress states influenced by passive arch action across a basal deflection plays a dominant role in mechanisms of weakening resistance against liquefaction and will contribute to embankments stability evaluation against earthquake.
National Committee for IUTAM, 2013, NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan, 62 (0), 114 - 114, Japanese- 建設工業調査会, 2013, ベース設計資料，No.158土木編（2013年後期版）, (No.158), 56 - 59, Japanese土構造物における観測化施工－性能設計下における建設イノベーションを目指して
Introduction other
- 地盤工学会, 2012, 地盤工学会誌, 60 (12), 17 - 17, Japanese圧密沈下(2)(4.地盤挙動,総括,<特集>第47回地盤工学会研究発表会)
- Jul. 2011, 土木技術 7月号, 66 (7), 23 - 27, Japanese国際的な性能設計化の潮流における地盤解析技術の役割
Introduction other
- Jan. 2010, 地盤工学会60周年記念号，地盤工学会誌, 58 (1), 40 - 41, Japanese地盤工学における数値解析技術
Introduction scientific journal
- 2010, 平成22年度 第28回神戸大学工学部公開講座・ひょうご講座，テーマ：スーパーコンピューティングが拓く明日の暮らし－システム情報学研究科発足によせて－, 11 - 16, Japanese地盤変状・塩害シミュレータを用いた合意形成の試み
Lecture materials
- Jun. 2009, 基礎工, 7, 32 - 35, Japanese不飽和土の力学理論から見た土の締固め
Introduction scientific journal
Statics of a sand heap under gravity associates to stress indeterminacy. The additional relationship is usually given by constitutive relations. Thus, radial stress field function satisfying plane equilibrium, constitutive relation and stress initial-boundary condition can provide a basic solution. Since stress distribution in sand heap is also depended on stress history during formation, therefore it is difficult to specify the constitutive relation which can characterize this complicated problem. The recent researches has linked arching criterion to describe a local constitutive relation and successfully captured a phenomenon of vertical pressure dip. However, a clear degree of arching effect to a stress distribution beneath the base of the heap has not been clarified. This study investigated the influence of arch shapes formed in sand heap and found particular patterns which are acceptably agreed with the experimental data. Therefore, arch formed during formation could be considered as stress memories of sand heap.
National Committee for IUTAM, 2009, NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan, 58 (0), 190 - 190, Japanese- 2009, Journal of Applied Mechanics JSCE, 12, 421 - 428Study of the stratigraphic architecture resistant for salt damage and the method to purify salty ground
- 2009, 土木学会応用力学論文集, 12, 383 - 394二次元砂山における静止土圧係数解析の原理
- Aug. 2008, 地盤工学会誌, Vol.56 (No.8), 52 - 52, Japanese平成19年度地盤工学会技術開発賞を受賞して，学会賞受賞報告
Introduction scientific journal
- Jul. 2008, 土/水連成有限要素解析を用いた各種外的要因による地盤内水分布変化, CD-ROM(pp.399-400), Japanese密な豊浦砂の降伏面と塑性ひずみ方向についての実験的検討
Others
- Dec. 2007, 土と基礎, Vol.55 (No.12), 14 - 16, Japanese地盤工学の限界と可能性 (技術者交流特別セッション,< 小特集> 第 42 回地盤工学研究発表会)
Introduction scientific journal
- Sep. 2007, 神戸大学最前線, 22 - 23, Japanese地球環境解析学―まずは小さな一歩から
Others
- タイ東北部の塩害調査と「ジグソー・ピーシス作戦」，論説
By a consequence of surveys on salt damage areas in the northeastern part of Thailand during October, 13-20, 2005 and November 26-29, 2006, a co-organized workshop on numerical method for unsaturated soil behaviors prediction was held in Bangkok on November 27, 2006. The sites and related organizations were visited to investigate the backgrounds of salt disaster. It was found that though each organization has clear different missions, there are some missing links among organizations to solve the salt disaster which is caused by multiple factors. It is expected that the workshop will be benefit to Thai experts while promoting mutual cooperation together.
地盤工学会, 01 Mar. 2007, 土と基礎, Vol.55 (No.3,Ser.No.590), 22 - 24, JapaneseIntroduction scientific journal
- Jan. 2007, 土と基礎, Vol.55 (No.1,SerNo.588), 6 - 7, Japanese地盤工学会・本部主催講習会のあり方について，論説
Introduction scientific journal
- Sep. 2006, 自然災害科学, Vol.25 (No.2), 233 - 249, Japanese平成18年(2006年)5月27日ジャワ島中部地震被害調査速報
Introduction scientific journal
- Jun. 2006, 基礎工 特集：圧密沈下の予測・対策の現状，総説, 34 (6), 8 - 11, Japanese「土構造物の品質」における圧密・変形予測
Introduction other
- Jun. 2006, 土木学会誌，Vol.91，p.21 建築雑誌，Vol.121，No.1548，p.22, Japanese価値観の混沌を抜け出し，次世代の手本となるトップランナーたれ，土木学会誌×建築雑誌 共同企画「子どもたちへのメッセージ」，40人の提言
Introduction scientific journal
- Apr. 2006, 関連報告：土木学会地盤工学委員会，土構造の性能評価に関する小委員会・WG(1)：盛土構造物の性能規定化における課題と展望，委員会報告，土木学会論文集C，土木学会, Vol.63 (No.4), 993 - 1000, Japanese欧州における性能設計を支える制度に関する調査報告 土木学会地盤工学委員会，土構造の性能評価に関する小委員会
- Jan. 2006, 地盤工学会誌「土と基礎」, Vol.54 (No.1,Ser.No.576), 1 - 4, Japanese地盤工学における技術者教育の意義と学会の役割，総説
Introduction scientific journal
- Dec. 2005, 土と基礎, Vol.53 (No.12), 21 - 24, Japanese新しい地圏環境を探る、環境・安全・情報
Introduction scientific journal
- 2005, Proceeding of the 16th International Conference on Soil Mechanics and Geotechnical Engineering, 3145 - 3147, EnglishTechnical session 1b: Laboratory testing(II): Strength, Large deformation and hydraulic properties
Introduction scientific journal
- 2005, 21世紀COEプログラム「都市地震工学の発展と体系化」, 96 (No.), 35 - 46地盤動態解析の基礎理論
- Dec. 2004, 土と基礎, Vol.52 (No.12,Ser.No.563), 115 - 118, Japanese第3期技術者教育委員会の取り組み, －試案プログラムの実施と国際化教育－
Introduction scientific journal
- Dec. 2004, 第39回地盤工学研究発表会特集号 土と基礎, Vol.52 (No.12,Ser.No.563), 46, Japanese総括,ディスカッションセッション18 土構造物の品質評価 －技術的アプローチを探るⅡ
Introduction scientific journal
- Jun. 2004, 第39回地盤工学研究発表会，ディスカッションセッション２, 8 - 15, Japanese地盤工学における継続教育 －G-CPDシステムの活用状況と今後－，「第３期技術者教育委員会の取り組み」
Introduction scientific journal
- Apr. 2004, 土と基礎, Vol.52 (No.4,Ser.No.555), 37, Japanese第2回アジア地域不飽和土国際会議開催報告
Introduction scientific journal
- Dec. 2003, 第38回地盤工学研究発表会特集号，土と基礎, Vol.51 (No.12), 19 - 20, Japanese総括，ディスカッションセッション12 土構造物の品質評価－技術的アプローチを探る
Introduction scientific journal
- Nov. 2003, 地質と調査 （通巻第97号）, (’03第3号), 10 - 15, Japanese地盤の変形解析の現状と将来展望，技術の現状とこれから求められるもの
Introduction other
- Jul. 2003, 第38回地盤工学研究発表会資料, Japanese継続教育の具体案－次期委員長として，「知識社会における地盤技術者の生涯教育と学会の役割」平成13年度~平成14年度技術者教育委員会成果報告書より
Others
- Mar. 2003, 土木学会誌, Vol.88, 62 - 65, Japanese神戸アラカルト－写真で見る－，親土木入門
Introduction scientific journal
- 2003, Soft Ground Engineering in Coastal Areas, 397 - 407,
- 2003, Soft Ground Engineering in Coastal Areas, 397 - 407,
- 日本塑性加工学会・シミュレーション統合システム分科会, Nov. 2002, 第16回塑性加工技術フォーラム「非金属材料の塑性変形」講演集, Japanese地盤の弾・(粘)塑性構成式 －地盤の変形シミュレーション－
Introduction other
- Sep. 2002, Proc. of 1st International Workshop on New Frontiers in Computational Geotechnics, EnglishApplication of an elasto-plastic model with subloading surface to compacted soils
Others
- Dec. 2001, 土と基礎, Vol.49 (No.12), Japanese編集後記
Introduction scientific journal
- Sep. 2001, Task Report, TC31 of ISSMGE, Proc. of 15th International Conference on Soil Mechanics and Geotechnical Enginerring (ICSMGE), EnglishGeotechnical education using full-scaled experiments
Others
- Aug. 2001, 土と基礎, Vol.49 (No.8), 31 - 36, Japanese6.地盤の変形、講座：有限要素法の基礎と地盤工学への応用
Introduction scientific journal
- Jul. 2001, 土と基礎, Vol.49 (No.7), 37 - 43, Japanese5.土と水の連成問題， 講座：有限要素法の基礎と地盤工学への応用
Introduction scientific journal
- Jun. 2001, 土と基礎, Vol.49 (No.6(巻頭言)), Japanese本号の編集にあたって
Introduction scientific journal
- 土木学会, May 2001, 土木学会誌5月号, Vol.86, 16 - 18, Japanese沈下・変形を予測する，特集「理論」と「経験」と地盤問題に挑む
Introduction scientific journal
- Aug. 2000, 「地盤工学における物理数学の応用に関する研究委員会」サマースクールテキスト, 1 - 245, Japanese物理数学的にみた土質力学
Lecture materials
- Nov. 1999, 現場技術3者のための土質工学講習会⑧テキスト, 1 - 36, Japanese地盤の変形、弾性論から見た地盤変形
Lecture materials
- Sep. 1999, 「地盤工学における物理数学の応用に関する研究委員会」プレ・サマースクールテキスト, 1 - 151, Japanese土質力学のバックグラウンド
Lecture materials
- Nov. 1998, ジオシンセティックス技術情報11月号, Vol.14 (No.3), 54 - 61, Japanese「現在」を知って「将来」を予測する―ジオシンセティックス補強土構造物を例にとって
Introduction scientific journal
- Jul. 1998, ジオシンセティックス技術情報7月号, Vol.13 (No.2), 27 - 30, Japaneseジオシンセティックス補強土構造物の限界状態設計 Proc.A.McGownによるKeynote lectureの紹介
Introduction scientific journal
- Mar. 1998, 土と基礎, Vol.46 (No.3), 26 - 26, Japanese第14回国際地盤工学会議報告，ディスカッションセッション，4.2地下構造物の施工事例と現場計測
Introduction scientific journal
- Jan. 1998, 地盤工学会講習会，これからの数値解析テキスト, 1 - 31, Japanese構成式・有効応力解析の基礎と静的解析事例
Lecture materials
- Jan. 1998, 講座 土と基礎テキスト, Japaneseベーン試験と一軸試験
Lecture materials
- Aug. 1996, Research Report, Dept. of Civil Engineering, Virginia Polytechnic Institute and State University, 1 - 56, EnglishA note on the elasto-viscoplastic formulation, Research Report
- Mar. 1996, 土木学会誌3月号, Vol.81, 32 - 35, Japanese同一教官による同一講義の実験
Introduction scientific journal
- Dec. 1994, 土と基礎, Vol.42 (No.12), 21 - 21, Japanese第29回土質工学研究発表会 総括，せん断（粘性土）
Introduction scientific journal
- Jul. 1994, 土と基礎, Vol.42 (No.7), 37 - 38, Japanese第13回 国際土質基礎工学会議報告 ディスカッションセッション 2・3地盤工学教育
Introduction scientific journal
- Nov. 1993, 土質工学における数値解析手法とその適用テキスト, 28 - 47, Japanese有限要素法による盛土地盤の変形と安定
Lecture materials
- Nov. 1993, AIT (Asia Institute of Technology) Library, GT32-1993, 1 - 129, EnglishLecture note of analytical methods in geotechnical engineering
Lecture materials
- 1993, 土と基礎, Vol.41 (No.9), 55 - 56, Japaneseコロラド見聞録
Introduction scientific journal
- Sep. 1992, 地盤工学における有限要素法入門講習会テキスト, 21 - 72, Japanese地盤の変形解析への適用―弾塑性もしくは弾粘塑性構成モデルを用いた試み
Lecture materials
- Mar. 1992, 地盤の変形の局所化に関する研究委員会、土質工学会 報告, Japaneseせん断帯生成シミュレーションにおける有限要素の選択について
- Oct. 1990, 土と基礎, Vol.38 (No.10), 59 - 59, Japanese第25回土質工学研究発表会 総括・一般報告，地盤の応力と変形
Introduction scientific journal
- Nov. 1988, 第36期第5回塑性工学部門委員会, 材料学会, 1 - 30, Japanese非共軸Cam-clay有限変形弾塑性論によるせん断帯の生成
- Oct. 1987, Research Report of Construction Laboratory, Dept. of Civil Engineering, Kyoto University, 1 - 36, EnglishDACSAR (Deformation Analysis Considering Stress-induced Anisotropy and Reorientation) Soil/water coupled F.E. program and its manual
Books etc
- Contributor, 第5章 安全と未来，15未来に対する私たちの責任（飯塚敦）, 神戸大学出版会,神戸新聞総合出版センター (発売), Mar. 2021, pp.118–125, Japanese, ISBN: 9784909364135美しい未来をつくるひとのための15のはなし
- Chapter 208. A method of measuring the specific surface area of bentonite for evaluation of the hydraulic performance of bentonite engineered barriers, CRC Press, 2014, pp.1285–1290, English, ISBN: 9781138027077Geomechanics from micro to macro : proceedings of the TC105 ISSMGE International Symposium on Geomechanics from Micro to Macro, Cambridge, UK, 1-3 September 2014
- Contributor, １５．防災・減災における国土強靱化について，－超広域・複合災害に備える－, 国土強靱化総合研究所,相模書房 (発売), Nov. 2013, pp.343-366, Japanese, ISBN: 9784782413050国土強靱化，日本を強くしなやかに （その３）
- Joint editor, Prologue. Chapter 1. Chapter 7. Chapter 10. Chapter 11. Chapter 14.Chapter 15. Chapter 22., Springer, Jul. 2013, English, ISBN: 9789400756748Geotechnical predictions and practice in dealing with geohazards
Scholarly book
- Chapter 13 Soil Mechanics "Constitutive Modelling for Soft Cohesive Soils", Springer Dordrecht Heidelberg London New York, Mar. 2011, pp.231-251, English, ISBN: 9789400704695Chapter 13 Soil Mechanics "Constitutive Modelling for Soft Cohesive Soils", Geotechnics and Earthquake Geotechnics towards Global Sustainability
Scholarly book
- Joint work, 第3章3.2.1，第3章3.3.6, 地盤工学会, Dec. 2007, p.82 pp.128-137, Japanese, ISBN: 9784886440792設計用地盤定数の決め方－土質編－
Scholarly book
- Joint work, 地盤工学会, Sep. 2003, Japanese, ISBN: 4886440673地盤技術者のためのFEMシリーズ② 弾塑性有限要素法がわかる
Textbook
- Joint work, TC6 of International Society of Soil Mechanics and Geotechnical Engineering, Apr. 2003, EnglishUnsaturated Soils -Geotechnical and Geoenvironmental Issues-
Others
- Joint work, 地盤工学会, Aug. 2002, Japanese, ISBN: 4886449506地盤工学理論シリーズ 地盤の変形解析
Scholarly book
- Joint work, 山海堂, Mar. 2000, Japanese, ISBN: 4381012747地盤力学
Scholarly book
- Joint work, 土木学会, Dec. 1996, Japanese, ISBN: 4810601730構造工学シリーズ７ 構造工学における計算力学の基礎と応用
Scholarly book
- Joint work, 土質工学会, Oct. 1994, Japanese, ISBN: 4886440487地盤の破壊とひずみの局所化
Scholarly book
Presentations
- 令和2年度土木学会全国大会(講演概要集 CS12-18), Sep. 2020, Japanese飽和ベントナイト供試体の吸水による側方膨潤シミュレーション
Oral presentation
- 第55回地盤工学研究発表会（オンライン）21-2-3-05, 23 Jul. 2020, Japanese不飽和ベントナイト供試体の吸水膨潤による隙間充填過程シミュレーション
Oral presentation
- 第55回地盤工学研究発表会（オンライン）23-1-4-08, 23 Jul. 2020, Japaneseせん断強度から不飽和土の圧縮・硬化特性を類推する方法の提案
Oral presentation
- 第55回地盤工学研究発表会（オンライン）23-7-3-08, 23 Jul. 2020, Japaneseベントナイト緩衝材を対象とした不飽和弾塑性構成モデルとパラメータ推定手法の提案
Oral presentation
- 第55回地盤工学研究発表会（オンライン）22-7-2-08, 22 Jul. 2020, Japanese盛土の遠心模型実験に対する動的数値シミュレーション
Oral presentation
- 第55回地盤工学研究発表会（オンライン）21-11-4-07, 21 Jul. 2020, Japanese液状化後の地盤沈下現象に着目した都市全体解析に関する研究～千葉県浦安市における測量結果との比較検討～
Oral presentation
- 第55回地盤工学研究発表会（オンライン）21-11-4-06, 21 Jul. 2020, Japanese液状化後の地盤沈下現象に着目した都市全体解析に関する研究～解析パラメータの同定～
Oral presentation
- 第55回地盤工学研究発表会（オンライン）21-10-1-07, 21 Jul. 2020, Japanese粘性曲面モデルを用いた二次圧密における層厚～載荷時間関係の表現
Oral presentation
- 第 54 回地盤工学研究発表会, Jul. 2019, Japanese, 地盤工学会, さいたま市, Japan, Domestic conference土水連成問題における分離型解法における反復試行の収束時のパラメータの推定
Oral presentation
- 第 54 回地盤工学研究発表会, Jul. 2019, Japanese, 地盤工学会, さいたま市, Japan, Domestic conferenceベントナイト緩衝材を対象とする不飽和弾塑性構成モデルの再現性評価
Oral presentation
- 第 54 回地盤工学研究発表会, Jul. 2019, Japanese, 地盤工学会, さいたま市, Japan, Domestic conference隙間充填過程を経たベントナイト緩衝材の変状シミュレーション
Oral presentation
- 第 54 回地盤工学研究発表会, Jul. 2019, Japanese, 地盤工学会, さいたま市, Japan, Domestic conferenceベントナイト緩衝材の膨潤圧発生機構についての解析的検討
Oral presentation
- 第 54 回地盤工学研究発表会, Jul. 2019, Japanese, 地盤工学会, さいたま市, Japan, Domestic conference不飽和土弾塑性構成モデルパラメータの同定法とその検証
Oral presentation
- 第 54 回地盤工学研究発表会, Jul. 2019, English, 地盤工学会, さいたま市, Japan, Domestic conferenceInfluence of Geometry and Soil Parameters in the Modelling of Embankment on Soft Soil Foundation
Oral presentation
- 第 54 回地盤工学研究発表会, Jul. 2019, Japanese, 地盤工学会, さいたま市, Japan, Domestic conference東京海抜ゼロメートル地帯における液状化解析
Oral presentation
- 第53回地盤工学研究発表会 (pp.1737-1738), Jul. 2018, Japanese, 地盤工学会, 高松市, Domestic conference分離型解法を用いた土／水連成問題の検討
Oral presentation
- 第53回地盤工学研究発表会 (pp.699-700), Jul. 2018, Japanese, 地盤工学会, 高松市, Domestic conference不飽和土の弾塑性構成モデルにおける硬化則に関するパラメータの推定手法
Oral presentation
- 第53回地盤工学研究発表会 (pp.1879-1880), Jul. 2018, Japanese, 地盤工学会, 高松市, Domestic conference東京海抜ゼロメートル地帯における地下水位変動に伴う液状化リスク
Oral presentation
- 第53回地盤工学研究発表会 （pp.741-742）, Jul. 2018, Japanese, 地盤工学会, 高松市, Domestic conference地層処分における再冠水から超長期変質過程の力学−水理−化学連成解析
Oral presentation
- 第53回地盤工学研究発表会 （793-794）, Jul. 2018, English, 地盤工学会, 高松市, Domestic conferenceNonlinearity and Uncertainty of Geotechnical Finite Element Analysis
Oral presentation
- 第53回地盤工学研究発表会 （pp.757-758）, Jul. 2018, Japanese, 地盤工学会, 高松氏, Domestic conferenceBjerrumの仮説に基づいた年代効果による疑似過圧密粘性土の圧密降伏応力の試算
Oral presentation
- 第53回地盤工学研究発表会（pp.365-366）, Jul. 2018, Japanese, 地盤工学会, 高松市, Domestic conference除荷過程における地盤材料の塑性軟化特性を考慮した弾塑性構成モデルの提案
Oral presentation
- 第53回地盤工学研究発表会 （pp.211-212）, Jul. 2018, Japanese, 地盤工学会, 高松市, Domestic conference海底地盤の原位置強度推定方法に関する解析的検討
Oral presentation
- 第53回地盤工学研究発表会（pp.345-346）, Jul. 2018, Japanese, 地盤工学会, 高松市, Domestic conferenceデコルマ帯における変質を考慮したせん断シミュレーション
Oral presentation
- 7th International Conference on Clays in Natural and Engineered Barriers for Radioactive Waste Confinement, Sep. 2017, English, Davos, Switzerland, International conferenceElastoplastic prediction of clay-buffer homogenization due to swelling behavior
Poster presentation
- 第52 回地盤工学研究発表会（T – 06 pp.61-62）, Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conferenceベイズ推定を用いた被害予測における死亡者数再現関数の検討
Oral presentation
- 第52 回地盤工学研究発表会 （E – 02 pp.757-758）, Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conference溶存気体の気化が真空圧密時の地盤内圧力変化に及ぼす影響
Oral presentation
- 第52 回地盤工学研究発表会 （D – 07 pp.591-592）, Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conference様々な応力条件におけるB 値測定手法の繰返し載荷の影響
Oral presentation
- 第52 回地盤工学研究発表会 （D – 05 pp.2055-2056）, Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conference密度差のある二つの締固めベントナイト供試体の直列膨潤圧試験シミュレーション
Oral presentation
- 第52 回地盤工学研究発表会 （E – 00 pp.1621-1622）, Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conference不飽和地盤の液状化強度発現に関する解析的研究
Oral presentation
- 第52 回地盤工学研究発表会（E – 02 pp.783-784）, Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conference不確かさを考慮した地盤解析結果の評価法
Oral presentation
- 第52 回地盤工学研究発表会 （E – 07 pp.1541-1542）, Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conference地盤動的解析のための試験結果のばらつきを考慮したパラメータ範囲の検討
Oral presentation
- 第52 回地盤工学研究発表会（E – 13 pp.1579-1580）, Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conference先行効果を考慮した弾・粘塑性構成モデルの動的解析への適用
Oral presentation
- 第52 回地盤工学研究発表会 （E – 02 pp.587-588）, Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conference深海底地盤からのサンプリング試料のモデル化に関する考察
Oral presentation
- 第52 回地盤工学研究発表会 （E – 02 pp.583-584）, Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conference三成分系状態図による締固め土の強度評価
Oral presentation
- 第52 回地盤工学研究発表会 （E – 02 pp.2069-2070）, Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conference化学変質によるベントナイト緩衝材の超長期挙動に及ぼす初期密度分布の影響
Oral presentation
- 第52 回地盤工学研究発表会 (E – 02 pp.655-656), Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conferenceデコルマ帯におけるせん断破壊モデル
Oral presentation
- 第52 回地盤工学研究発表会 (E – 00 pp.303-304), Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conferenceデコルマ帯におけるスロースリップの弾塑性論的解釈
Oral presentation
- 第52 回地盤工学研究発表会 (K – 14 pp.489-490), Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conferenceジオテキスタイルを用いた補強土の補強効果の評価手法
Oral presentation
- 第52 回地盤工学研究発表会 (E – 13 pp.1805-1806), Jul. 2017, Japanese, 地盤工学会, 名古屋市, Domestic conferenceSPH 法を用いた仮置き盛土に対する安全性検討
Oral presentation
- BEACON Initial Workshop, Jun. 2017, EnglishResearch activities at RWMC on the bentonite re-saturation process (2) Laboratory and numerical evaluation
Poster presentation
- 第51回地盤工学研究発表会 (CD-ROM0365 pp.729-730), Sep. 2016, Japanese, 地盤工学会, 岡山市, Domestic conference放射性廃棄物地層処分におけるベントナイト緩衝材の変質評価
Oral presentation
- 第51回地盤工学研究発表会 (CD-ROM0188 pp.375-376), Sep. 2016, Japanese, 地盤工学会, 岡山市, Domestic conference粘性曲面モデルを用いた構造の発達・劣化の表現
Oral presentation
- 第51回地盤工学研究発表会 (CD-ROM0347 pp.693-694), Sep. 2016, Japanese, 地盤工学会, 岡山市, Domestic conference間隙保水特性と非可逆変形特性が B 値発現に及ぼす影響
Oral presentation
- 第51回地盤工学研究発表会 (CD-ROM0346 pp.691-692), Sep. 2016, Japanese, 地盤工学会, 岡山市, Domestic conference海底地盤から採取したサンプリング試料の強度発現メカニズム
Oral presentation
- 第51回地盤工学研究発表会 (CD-ROM0059 pp.117-118), Sep. 2016, Japanese, 地盤工学会, 岡山市, Domestic conferenceベイズ推定を用いた被害予測モデルと災害対応におけるタイムライン分析
Oral presentation
- 第51回地盤工学研究発表会 (CD-ROM0369 pp.737-738), Sep. 2016, Japanese, 地盤工学会, 岡山市, Domestic conferenceデコルマ帯における固着メカニズムの解明
Oral presentation
- 第51回地盤工学研究発表会 (CD-ROM0786 pp.1571-1572), Sep. 2016, Japanese, 地盤工学会, 岡山市, Domestic conferenceジオテキスタイル補強土構造物における補強効果の検討
Oral presentation
- 51回地盤工学研究発表会 (CD-ROM0035 pp.69-70), Sep. 2016, Japanese, 地盤工学会, 岡山市, Domestic conferenceTC106 Unsaturated soils における世界的な動向
Oral presentation
- 平成28年度土木学会全国大会，第71回年次学術講演会 (CS13-039 pp.77-78), Sep. 2016, Japanese, 土木学会, 仙台市, Domestic conference高レベル放射性廃棄物の地層処分における緩衝材の再冠水挙動に関する解析的検討
Oral presentation
- 日本災害情報学会第17回研究発表大会, Oct. 2015, Japanese, 甲府, Domestic conferenceワイブル分布を用いた災害死亡者数のベイズ推定モデル
Oral presentation
- 第50回地盤工学研究発表会 （D-00 pp.693-694）, Sep. 2015, Japanese, 地盤工学会, 札幌, Domestic conference応力履歴がB 値発現に及ぼす影響（実験）
Oral presentation
- 第50回地盤工学研究発表会（E-00 pp.695-696）, Sep. 2015, Japanese, 地盤工学会, 札幌, Domestic conference応力履歴がB 値発現に及ぼす影響（解析）
Oral presentation
- 第50回地盤工学研究発表会（E-02 pp.447-448）, Sep. 2015, Japanese, 地盤工学会, 札幌Albany硅砂の弾塑陸構成パラメータの同定
Oral presentation
- 第50回地盤工学研究発表会 (T-14 pp.2295-2296), Sep. 2015, Japanese, 地盤工学会, 札幌, Domestic conference粒度分布に注目した土粒子吸着物質の除去法の検討
Oral presentation
- 第50回地盤工学研究発表会 (E-07 pp.63-64), Sep. 2015, Japanese, 地盤工学会, 札幌, Domestic conference覆土工における排水能力の評価
Oral presentation
- 平成27年度土木学会全国大会，第70回年次学術講演会 (Ⅴ-302), Sep. 2015, Japanese, 土木学会, 岡山, Domestic conference複数種の補強繊維を使用した軽量セラミックスの強度特性について
Oral presentation
- 第50回地盤工学研究発表会 (D-06 pp.365-366), Sep. 2015, Japanese, 地盤工学会, 札幌, Domestic conference非線形コントラクタンシー表現式を用いた弾塑性構成モデルの破壊規準の改良
Oral presentation
- 平成27年度土木学会全国大会，第70回年次学術講演会 (CS12-031), Sep. 2015, Japanese, 土木学会, 岡山, Domestic conference地層処分における緩衝材の再冠水挙動に関する解析的検討
Oral presentation
- 第50回地盤工学研究発表会 (H-11 pp.2375-2376), Sep. 2015, Japanese, 地盤工学会, 札幌, Domestic conference地層処分におけるベントナイト緩衝材の変質挙動評価
Oral presentation
- 第50回地盤工学研究発表会 (B-06 pp.369-370), Sep. 2015, Japanese, 地盤工学会, 札幌, Domestic conference深海底デコルマ帯の変質を考慮したせん断破壊モデル
Oral presentation
- 第50回地盤工学研究発表会 (E-07 pp.2101-2102), Sep. 2015, Japanese, 地盤工学会, 札幌, Domestic conference降雨時の傾斜地盤内における空気圧の挙動について
Oral presentation
- 第50回地盤工学研究発表会 (H-07 pp.1069-1070), Sep. 2015, Japanese, 地盤工学会, 札幌, Domestic conference気相の影響を考慮した河川堤防の外水位変動シミュレーション
Oral presentation
- 第50回地盤工学研究発表会 (E-13 pp.399-400), Sep. 2015, Japanese, 地盤工学会, 札幌, Domestic conference関口・太田による弾・粘塑性構成モデルにおける応力緩和項の定式化について
Oral presentation
- 第50回地盤工学研究発表会 (E-00 pp.711-712), Sep. 2015, Japanese, 地盤工学会, 札幌, Domestic conference海底地盤からのサンプリングに伴う応力変化が強度特性に及ぼす影響
Oral presentation
- 平成27年度土木学会全国大会，第70回年次学術講演会 (Ⅳ-043), Sep. 2015, Japanese, 土木学会, 岡山, Domestic conferenceワイブル分布による被災者数のベイズ推定
Oral presentation
- 第50回地盤工学研究発表会 (D-00 pp.735-736), Sep. 2015, Japanese, 地盤工学会, 札幌, Domestic conferenceベンダーエレメントを用いた不飽和供試体のせん断弾性定数
Oral presentation
- 第50回地盤工学研究発表会（B-06 pp.371-372）, Sep. 2015, Japanese, 地盤工学会, 札幌, Domestic conferenceスメクタイトの変質作用がデコルマ帯におけるせん断特性に及ぼす影響
Oral presentation
- 日本災害情報学会第16回研究発表大会, Oct. 2014, Japanese, 長岡ベイズ推定を用いた災害時の被災者数予測
Oral presentation
- 第69回土木学会年次学術講演会（Ⅲ-364 pp.727-728）, Sep. 2014, Japanese, 土木学会, 大阪, Domestic conference廃砂たい積場の覆土設置による沈下の評価
Oral presentation
- 第69回土木学会年次学術講演会（CS9-010 pp.19-20）, Sep. 2014, Japanese, 土木学会, 大阪, Domestic conference土の粒度分布に注目した放射性物質吸着土壌の減容化に関する検討
Oral presentation
- 第49回地盤工学研究発表会 （講演概要集DVD/352 pp.703-704）, Jul. 2014, Japanese, 地盤工学会, 北九州, Domestic conference液相への間隙空気溶解を考慮した室内要素試験シミュレーション
Oral presentation
- 第49回地盤工学研究発表会 （講演概要集DVD/348 pp.695-696）, Jul. 2014, Japanese, 地盤工学会, 北九州, Domestic conference土／水／空気有限要素解析を用いた河川堤防における浸潤面の形成メカニズムの再現（1）
Oral presentation
- 第49回地盤工学研究発表会(講演概要集DVD/347 pp.693-694), Jul. 2014, Japanese, 地盤工学会, 北九州, Domestic conference土／水／空気連成有限要素解析を用いた河川堤防における浸潤面の形成メカニズムの再現（2）
Oral presentation
- 第49回地盤工学研究発表会（講演概要集DVD/1052 pp.2103-2104）, Jul. 2014, Japanese, 地盤工学会, 北九州長期化学的変質を考慮したベントナイト緩衝材の力学モデルと境界値問題の定式化
Oral presentation
- 第49回地盤工学研究発表会 （講演概要集DVD/503 pp.1005-1006）, Jul. 2014, Japanese, 地盤工学会, 北九州, Domestic conference東名牧の原崩壊盛土の原位置強度推定の試み
Oral presentation
- 第49回地盤工学研究発表会 （講演概要集DVD/447 pp.893-894）, Jul. 2014, Japanese, 地盤工学会, 北九州, Domestic conference土／水／空気連成モデルによる降雨浸透解析
Oral presentation
- 第49回地盤工学研究発表会（講演概要集DVD/448 pp.895-896）, Jul. 2014, Japanese, 地盤工学会, 北九州, Domestic conference降雨浸透シミュレーションにおける浸透能の影響について
Oral presentation
- 第49回地盤工学研究発表会（講演概要集DVD/1051 pp.2101-2102）, Jul. 2014, Japanese, 地盤工学会, 北九州, Domestic conference化学変質を考慮したベントナイト緩衝材の力学モデル
Oral presentation
- 第49回地盤工学研究発表会 （講演概要集DVD/445 pp.889-890）, Jul. 2014, Japanese, 地盤工学会, 北九州, Domestic conferenceタイ東北部における塩害抑制手法の検討
Oral presentation
- 第68回土木学会年次学術講演会 ( CS部門 pp.57-58), 01 Sep. 2013, Japanese, 土木学会, 東京, Domestic conference土質力学から見たベントナイト材料の特異性と構成モデル化
Oral presentation
- 第68回土木学会年次学術講演会(CS部門 pp.41-42), Sep. 2013, Japanese, 土木学会, 東京, Domestic conference長期的化学変質作用を考慮するためのベントナイト緩衝材の力学モデル化
Oral presentation
- 第68回土木学会年次学術講演会(III部門 pp.377-378), Sep. 2013, Japanese, 土木学会, 東京, Domestic conference廃砂たい積場の覆土設置による沈下及び覆土の排水機能の評価
Oral presentation
- 第68回土木学会年次学術講演会 (CS部門 pp.59-60), Sep. 2013, Japanese, 土木学会, 東京, Domestic conferenceベントナイト材料の実験結果から得た構成モデルを用いた各種室内試験の解析
Oral presentation
- 第68回土木学会年次学術講演会 (III部門 pp.373-374), Sep. 2013, Japanese, 土木学会, 東京, Domestic conference土壌種類に起因する塩類の移動性の違い
Oral presentation
- 第 48 回地盤工学研究発表会 (講演概要集DVD pp.2159-2160 ), Jul. 2013, Japanese, 地盤工学会, 富山, Domestic conference粒度分布を考慮した土粒子のイオン吸着試験
Oral presentation
- 第 48 回地盤工学研究発表会 (講演概要集DVD pp.1001-1002), Jul. 2013, Japanese, 地盤工学会, 富山, Domestic conference二次圧密による擬似過圧密化を考慮した弾・粘塑性構成モデル
Oral presentation
- 第 48 回地盤工学研究発表会 (講演概要集DVD pp.481-482), Jul. 2013, Japanese, 地盤工学会, 富山, Domestic conference東名牧の原崩壊盛土材料の締固め－定体積単純せん断強度特性
Oral presentation
- 第 48 回地盤工学研究発表会 (講演概要集DVD pp.1959-1960), Jul. 2013, Japanese, 地盤工学会, 富山, Domestic conference土/水連成有限要素法を用いた降雨時斜面安定に関する各種要因の検討
Oral presentation
- 第 48 回地盤工学研究発表会 (講演概要集DVD pp.391-392), Jul. 2013, Japanese, 地盤工学会, 富山, Domestic conference数値計算による異なる含水比で締固め度の等しい締固め地盤の品質評価
Oral presentation
- 第 48 回地盤工学研究発表会 (講演概要集DVD pp.229-230), Jul. 2013, Japanese, 地盤工学会, 富山, Domestic conference構造物に近接する埋立て工事に対するロバスト制御アプローチの適用
Oral presentation
- 第 48 回地盤工学研究発表会 (講演概要集DVD pp.465-466), Jul. 2013, Japanese, 地盤工学会, 富山, Domestic conference過圧密粘土の三軸繰返しせん断による変形強度特性の変化
Oral presentation
- 第62回理論応用力学講演会(NCTAM2013)，OS20-01, Mar. 2013, Japanese, 東京都, Domestic conference東日本大震災の津波による地盤塩害及び土壌汚染調査・分析
Keynote oral presentation
- 第67回土木学会年次学術講演会 （III部門 pp.131-132）, 01 Sep. 2012, Japanese, 土木学会東日本大震災における津波由来土壌汚染調査
Oral presentation
- 第47回地盤工学研究発表会 （pp.636-364）, Jul. 2012, Japanese, 地盤工学会Weight transmission in conical sand pits stored in a rectangular bin, The 47th Japan National Conference on Geotechnical Engineering
Oral presentation
- 第47回地盤工学研究発表会 （pp.745-746）, Jul. 2012, Japanese, 地盤工学会, 八戸神戸空港島の経年沈下解析
Oral presentation
- 第47回地盤工学研究発表会 （pp.37-38）, Jul. 2012, Japanese, 地盤工学会, 八戸沈降海浜部地盤内の塩分移動予測及び一本松保護
Oral presentation
- 第47回地盤工学研究発表会 （pp.21-22）, Jul. 2012, Japanese, 地盤工学会, 八戸土／水／空気連成有限要素解析プログラムによる締固め施工を考慮した築堤シミュレーション
Oral presentation
- 第47回地盤工学研究発表会（pp.23-24）, Jul. 2012, Japanese, 地盤工学会, 八戸締固めシミュレーションに及ぼす土質物性の影響
Oral presentation
- 第47回地盤工学研究発表会 （pp.1957-1958）, Jul. 2012, Japanese, 地盤工学会, 八戸東日本大震災の津波による地盤塩害の調査・分析
Oral presentation
- 第47回地盤工学研究発表会 (pp.1945-1946), Jul. 2012, Japanese, 地盤工学会, 八戸TRU廃棄物処分場における緩衝材の力学・化学連成解析
Oral presentation
- 第46回地盤工学研究発表会 (講演集 pp.697-698), Jul. 2011, Japanese, 地盤工学会, 神戸, Domestic conference土／水／空気連成有限要素解析プログラムを用いた「締固め」の力学的説明
Oral presentation
- 第46回地盤工学研究発表会 (講演集 pp.685-686), Jul. 2011, Japanese, 地盤工学会, 神戸, Domestic conference弾塑性構成理論に基づくベントナイトの吸水膨潤特性の表現
Oral presentation
- 第46回地盤工学研究発表会 (講演集 pp.1009-1010), Jul. 2011, Japanese, 地盤工学会, 神戸, Domestic conference荷重載荷による飽和／不飽和地盤内溶解物質の移動表現
Oral presentation
- 弟21回国際開発学会全国大会(The Proc 21st Annual Conference of the Japan Society for International Development 「弟21回国際開発学会全国大会報告論文集」 pp. 227-228), Dec. 2010, Japanese, 国際開発学会, 東京, Domestic conferenceSaline soil problems in the northeastern part of Thailand and development of a computing tool for inter-organization collaboration
Oral presentation
- 第45回地盤工学研究発表会 (講演集 pp.231-232), Aug. 2010, Japanese, 地盤工学会, 愛媛, Domestic conference下負荷面･上負荷面を考慮した関口･太田モデルの特異点処理法
Oral presentation
- 第45回地盤工学研究発表, Aug. 2010, Japanese, 地盤工学会, 松山, Domestic conference土/水連成有限要素解析プログラムを用いた締固め土の品質の検討
Oral presentation
- 第45回地盤工学研究発表会, Aug. 2010, Japanese, 地盤工学会, 松山, Domestic conference土/水/空気連成有限要素解析による締固めシミュレーション
Oral presentation
- 第45回地盤工学研究発表会, Aug. 2010, Japanese, 地盤工学会, 松山, Domestic conference地下水位変動による地盤挙動の解釈
Oral presentation
- 第45回地盤工学研究発表会, Aug. 2010, Japanese, 地盤工学会, 松山, Domestic conference下負荷面を用いた不飽和土における降伏面内の弾塑性挙動のモデル化
Oral presentation
- 第64回土木学会年次学術講演会 (議講演概要集 III部門 pp.669-670), Sep. 2009, Japanese, 土木学会, 福岡, Domestic conference斜面形状による築堤時の発現応力の違い
Oral presentation
- 第44回地盤工学研究発表会 (講演集 pp.973-974), Aug. 2009, Japanese, 地盤工学会, 横浜, Domestic conference不飽和土弾塑性構成モデルを用いた築堤シミュレーション
Oral presentation
- 第44回地盤工学研究発表会 (講演集 pp.481-482), Aug. 2009, Japanese, 地盤工学会, 横浜, Domestic conference多孔質セラミック粒状体の一次元圧縮特性と破砕性
Oral presentation
- 第44回地盤工学研究発表会 (講演集 pp.913-914), Aug. 2009, Japanese, 地盤工学会, 横浜, Domestic conference気候条件に伴う塩害の被害及び対策
Oral presentation
- 第44回地盤工学研究発表会(講演集 pp.655-656), Jul. 2009, Japanese, 地盤工学会, 博多, Domestic conference土/水連成有限要素解析プログラムを用いた締固め曲線の表現
Oral presentation
- 第58回理論応用力学講演会 NCTAM2009 (講演論文集 pp.391-392), Jun. 2009, Japanese, Statics of a sand heap under gravity associates to stress indeterminacy. The additional relationship is usually given by constitutive relations. Thus, radial stress field function satisfying plane equilibrium, constitutive relation and stress initial-boundary condition can provide a basic solution. Since stress distribution in sand heap is also depended on stress history during formation, therefore it is difficult to specify the constitutive relation which can characterize this complicated problem. The recent researches has linked arching criterion to describe a local constitutive relation and successfully captured a phenomenon of vertical pressure dip. However, a clear degree of arching effect to a stress distribution beneath the base of the heap has not been clarified. This study investigated the influence of arch shapes formed in sand heap and found particular patterns which are acceptably agreed with the experimental data. Therefore, arch formed during formation could be considered as stress memories of sand heap.Analyses of pressure distribution under 2D sand heap by considering arching effect「アーチ効果を考慮した二次元砂山底面での圧力分布解析」
Oral presentation
- 第5回地盤工学会関東支部発表会「Geo-Kanto 2008」(pp.350-355), Nov. 2008, Japanese, 地盤工学会陰解応力積分法を導入した地盤構成式の検討
Oral presentation
- 第5回地盤工学会関東支部発表会 (発表講演集 地盤工学会 pp.40-45), Oct. 2008, Japanese, 地盤工学会1次元圧密解析による盛土の沈下計算－現場実測データならびに2次元土・水連成解析とくらべて－
Oral presentation
- 第63回年次学術講演会 （講演概要集 III部門 pp.483-484）, Sep. 2008, Japanese, 土木学会破砕によるコントラクタンシー特性変化を考慮した岩石材料の弾塑性構成モデル
Oral presentation
- 第63回年次学術講演会 （講演概要 III部門 pp.627-628）, Sep. 2008, Japanese, 土木学会施工速度の違いが盛土基礎地盤の変形に与える影響
Oral presentation
- 第63回年次学術講演会（講演概要集 III部門 pp.901-902）, Sep. 2008, Japanese, 土木学会, 仙台, Domestic conference汚泥焼成土の基礎力学特性
Oral presentation
- 第43回地盤工学研究発表会 (講演概要集 pp.399-400 CD-ROM）, Jul. 2008, Japanese, 地盤工学会密な豊浦砂の降伏面と塑性ひずみ方向についての実験的検討
Oral presentation
- 第43回地盤工学研究発表会 (講演概要集 pp.1113-1114 CD-ROM), Jul. 2008, Japanese, 地盤工学会軟弱地盤上の道路盛土における性能指標の検討
Oral presentation
- 第43回地盤工学研究発表会（講演概要集 pp.265-266 CD-ROM）, Jul. 2008, Japanese, 地盤工学会静止土圧係数の解析
Oral presentation
- 第43回地盤工学研究発表会（講演概要集 pp.289-290 CD-ROM）, Jul. 2008, Japanese, 地盤工学会関口・太田モデルの特異点における負荷判定法
Oral presentation
- 第43回地盤工学研究発表会 （講演概要集 pp.2155-2156 CD-ROM）, Jul. 2008, Japanese, 地盤工学会, 広島, Domestic conference植生の吸水作用が地盤の変形に及ぼす影響
Oral presentation
- 第43回地盤工学研究発表会（講演概要集 pp.715-716 CD-ROM）, Jul. 2008, Japanese, 地盤工学会土/水連成有限要素解析を用いた各種外的要因による地盤内水分布変化
Oral presentation
- 理論応用力学講演会 （講演論文集 pp.355-356）, Jun. 2008, Japanese, Metastable domain of strain rate enclosed at the corner of the Sekiguchi-Ohta model is formulated in principal strain space. It was confirmed that this domain is bounded by elliptical curve in pi plane. The proposed referenced basis is useful to represent state of stress on regular yield surface and strain increment in metastable domain. Centroid of the domain is referred to the at-rest state under Ko condition.Domain of metastability at the corner of the Sekiguchi-Ohta model
Oral presentation
- 第4回地盤工学会関東支部発表会 (発表講演集 pp.455-460）, Oct. 2007, Japanese, 地盤工学会オリジナル･カムクレイと修正カムクレイの比較―故きを温ね，新しきを知る－
- 第42回地盤工学研究発表会 (講演概要集 pp.263-264 CD-ROM), Jul. 2007, Japanese, 地盤工学会弾塑性構成モデルのMetastability 特性とその定量化
Oral presentation
- 第42回地盤工学研究発表会 (講演概要集 pp.253-254 CD-ROM), Jul. 2007, Japanese, 地盤工学会盛土を載荷した軟弱地盤の力学挙動に対するClass A 予測
Oral presentation
- 第42回地盤工学研究発表会 (講演概要集 pp.265-266 CD-ROM), Jul. 2007, Japanese, 地盤工学会関口・太田モデルにおける陽解積分法を用いた応力更新アルゴリズム（Substepping schemes for the numerical integration of the Sekiguchi-Ohta model）
Oral presentation
- 第42回地盤工学研究発表会 (講演概要集 pp.261-262 CD-ROM), Jul. 2007, Japanese, 地盤工学会関口・太田による弾粘塑性構成モデルにおける負荷判定の改良
Oral presentation
- 第42回地盤工学研究発表会 (講演概要集 pp.227-228 CD-ROM), Jul. 2007, Japanese, 地盤工学会ダイレタンシー特性の表現の異なる弾塑性構成モデルに対するせん断帯生成解析
Oral presentation
- 第42回地盤工学研究発表会 (講演概要集 地盤工学会 CD-ROM), Jul. 2007, Japanese, 地盤工学会, 名古屋, Domestic conference締固め曲線と圧縮曲線の関連性について
Oral presentation
- 第42回地盤工学研究発表会(講演概要集 pp.1-2 CD-ROM), Jul. 2007, Japanese, 地盤工学会, 名古屋, Domestic conference地球環境問題の階層的整理と砂漠化問題の位置付け
Oral presentation
- 平成19年度土木学会関西支部年次学術講演会(講演概要集 第3部門 CD-ROM), May 2007, Japanese, 土木学会関西支部数値シミュレーションによる地圏・気圏間水循環に影響を及ぼす地下ダムの影響検討
Oral presentation
- 平成19年度土木学会関西支部年次学術講演会(講演概要集 第3部門 CD-ROM), May 2007, Japanese, 土木学会関西支部境界端面の潤滑性に注目した粘土供試体のせん断シミュレーション
Oral presentation
- 第3回地盤工学会関東支部研究発表会 (発表講演集 地盤工学会 pp.309-312), Nov. 2006, Japanese, 地盤工学会異方圧密粘土を想定した弾塑性構成モデルの破壊条件とKo条件の理論式；Geo-Kanto 2006
Oral presentation
- 第41回地盤工学研究発表会 (講演概要集 pp.315-316 CD-ROM), Jul. 2006, Japanese, 地盤工学会関口・太田による弾・粘塑性モデルにおける応力緩和項へのマクローリン展開の適用
Oral presentation
- 第41回地盤工学研究発表会 (講演概要集 pp.317-318 CD-ROM), Jul. 2006, Japanese, 地盤工学会拡張下負荷面を導入した弾塑性構成モデルの陰解積分アルゴリズム
Oral presentation
- 第41回地盤工学研究発表会 (講演概要集 pp.319-320 CD-ROM), Jul. 2006, Japanese, 地盤工学会陰解積分アルゴリズムの境界値問題への適用性の検討
Oral presentation
- 第41回地盤工学研究発表会 (講演概要集 pp.321-322 CD-ROM), Jul. 2006, Japanese, 地盤工学会一次関数近似を用いた水頭の空間離散化
Oral presentation
- 第41回地盤工学研究発表会(講演概要集 pp.849-850 CD-ROM), Jul. 2006, Japanese, 地盤工学会, 鹿児島, Domestic conference上負荷面を用いた締固め粘性土の排気非排水せん断挙動の表現方法
Oral presentation
- 第41回地盤工学研究発表会(講演概要集 pp.847-848 CD-ROM), Jul. 2006, Japanese, 地盤工学会, 鹿児島, Domestic conference上負荷面を用いた締固め粘性土の等体積せん断挙動の表現方法
Oral presentation
- 第１０回震災技術展，神戸会場，「安全・安心」への国際協力の現状と課題, Jan. 2006, Japanese, 神戸市防災安全公社, 神戸, Domestic conference共生への国際技術協力の可能性 タイ東北部における塩害調査
Invited oral presentation
- 第６０回年次学術講演会 (講演概要集 III部門 pp.247-248 CD-ROM), Sep. 2005, Japanese, 土木学会, 東京, Domestic conference締固め土の体積圧縮挙動に着目した応力ひずみ関係の定式化
Oral presentation
- 第４０回地盤工学研究発表会 (講演集 pp.899-900), Jul. 2005, Japanese, 地盤工学会, 函館, Domestic conference締固め土の圧縮特性に関する評価方法
Oral presentation
- 第４０回地盤工学研究発表会 (講演集 pp.941-942), Jul. 2005, Japanese, 地盤工学会, 函館, Domestic conference植生による蒸発散量を考慮した不飽和地盤の変形挙動予測
Oral presentation
- 第４０回地盤工学研究発表会 (講演集 pp.983-984), Jul. 2005, Japanese, 地盤工学会, 函館, Domestic conference関口・太田モデルの圧密特性と粘塑性パラメータ
Oral presentation
- 第40回地盤工学研究発表会講演集, Jul. 2005, Japanese, 地盤工学会, 函館, Domestic conference下負荷面を導入した弾塑性構成モデルの陰解積分アルゴリズム
Oral presentation
- 第40回地盤工学研究発表会講演集, Jul. 2005, Japanese, 地盤工学会, 函館, Domestic conference陰解法アルゴリズムに基づく有限変形弾塑性有限要素解析
Oral presentation
- 第４０回地盤工学研究発表会 (講演集，pp.573-574), Jul. 2005, Japanese, 地盤工学会, 函館, Domestic conference陰解積分法を用いた関口・太田による弾・粘塑性モデルに対する応力更新アルゴリズム
Oral presentation
- 第４０回地盤工学研究発表会 (講演集 pp.1099-1100), Jul. 2005, Japanese, 地盤工学会, 函館, Domestic conferenceSCP工法を伴う防波堤の長期的品質予測
Oral presentation
- 11th International Association for Computer Methods and Advances in Geomechanics, Jun. 2005, English, プラハ, International conferenceInfluence of ground improvement on the quality of man-made islands
Oral presentation
- 土木学会関西支部年次学術講演会講演概要集(CD-ROM), 29 May 2005, Japanese不飽和地盤への降雨のモデル化
- 土木学会関西支部年次学術講演会講演概要集(CD-ROM), 29 May 2005, Japanese実験土槽における降雨浸透特性
- 植生学会第9回大会, Oct. 2004, Japanese, 植生学会蒸発散に伴う地盤の応答
Oral presentation
- 平成16年度京都大学防災研究所研究集会(一般)「流体―不飽和土系ダイナミクスの最近の進歩と環境防災への適用」, Sep. 2004, Japanese不飽和地盤―気圏間の水収支における植生の影響
- 第59回年次学術講演会 (概要集 III部門 pp.103-104 CD-ROM3-052), Sep. 2004, Japanese, 土木学会不飽和地盤に及ぼす植物の吸水作用の影響
Oral presentation
- 第59回年次学術講演会 (概要集 III部門 pp.551-552 CD-ROM3-276), Sep. 2004, Japanese, 土木学会正規圧密年度の瞬間せん断剛性の軸圧縮履歴依存性
Oral presentation
- 第59回年次学術講演会 (概要集 III部門 pp.655-656), Sep. 2004, Japanese, 土木学会初期値境界値問題における地表面水理境界による降雨表現の検討
Oral presentation
- 第59回年次学術講演会 (概要集 III部門 pp.651-652), Sep. 2004, Japanese, 土木学会降雨に伴う土槽内の飽和度サクション分布の変化
Oral presentation
- 第39回地盤工学研究発表会 (講演集 pp.259-260), Jul. 2004, Japanese, 地盤工学会対数ひずみを用いた有限変形Cam-clayモデルの陰解法アルゴリズム
Oral presentation
- 第39回地盤工学研究発表会 (講演集 pp.913-914), Jul. 2004, Japanese, 地盤工学会関口・太田モデルにおける塑性論的粘塑性論に基づく負荷判定法の適用性
Oral presentation
- 第39回地盤工学研究発表会 (講演集 pp.261-262), Jul. 2004, Japanese, 地盤工学会適用性の高いダイレイタンシーの表現式の提案とそれを用いた土の弾塑性構成式の導出
Oral presentation
- 第39回地盤工学研究発表会講演論文集, 2004盛土構造物の建設における軟弱地盤対策工の工学的評価
- 第38回地盤工学研究発表会 (講演集 CD-ROM147 pp.293-294）, Jul. 2003, Japanese, 地盤工学会Mises規準から見た境界非排水粘土供試体の破壊シミュレーション －Mises型かMohr-Coulomb型か－
Oral presentation
- 第38回地盤工学研究発表会 (講演集 CD-ROM677 pp.1353-1354）, Jul. 2003, Japanese, 地盤工学会, 道路盛土および人工島などに挙げられる土構造物が供用後の不同沈下等により要求される性能(要求性能)が低下する事例がよく見られる.このため,初期投資だけでなく維持補修時に要するコストを含めたライフサイクルコストの低減できるような技術システムを構築が求められている.本報告はサンドドレーンによる地盤改良時期・場所の違いにより埋立地がどのように長期的に変状するかを二次元土/水連成弾・粘塑性有限要素解析により検討したものである.地盤改良時期および位置が残留沈下に及ぼす影響
Oral presentation
- 第38回地盤工学研究発表会 (講演集 CD-ROM456 pp.911-912）, Jul. 2003, Japanese, 地盤工学会, 近年、谷地形に大規模な盛土を行った土構造物が多く見られるが、長期の雨水浸透により盛土の品質が劣化し、盛土表面に不同沈下が生じてしまうという事例が報告されている。締固め土のような不飽和土は水浸させることにより,水浸沈下(コラプス)が生じることがわかっている。長期にわたり降雨が繰り返されることにより地盤内に局所的で短時間の水浸状態が繰り返し発生していると考えられ、盛土内に局所的な変形が生じることで不同沈下が生じていると考えられる。そこで仮想の谷地形盛土を想定し、不飽和土/水連成有限要素解析によって、水浸沈下による盛土の不同沈下を表現した。谷地形盛土の不同沈下シミュレーション
Oral presentation
- 第38回地盤工学研究発表会 (講演集，地盤工学会，CD-ROM248 pp.495-496）, Jul. 2003, Japanese, 地盤工学会, 砂の再液状化特性は、その内部構造と密接に関わっていると考えられている。本研究では、この砂の再液状化特性を数値解析により表すことを目的としている。本研究では、砂の粒子配列を応力の異方性(降伏面の傾き)と考える。さらに、砂の嵩高な構造を考慮するために、上負荷面の概念を導入する。また、繰返し載荷への適用性を考慮し、拡張下負荷面、回転硬化を弾塑性構成式に導入する。応力振幅一定繰返し非排水せん断シミュレーションを通して、本弾塑性構成モデルの再液状化現象への適用性を検討した。結果として、砂の内部構造を、応力の異方性と上負荷面としてモデル化することの妥当性を示すことができた。上・拡張下負荷面,回転硬化を導入した弾塑性構成式による砂の再液状化特性の表現
Oral presentation
- 第38回地盤工学研究発表会 (講演集 CD-ROM676 pp.1351-1352）, Jul. 2003, Japanese, 地盤工学会, 従来,道路盛土および人工島などに挙げられる土構造物の設計は,施工(荷重)履歴の違いが与える構造物自身あるいは基礎地盤の品質の影響を考慮するには至らなかった.これに対し,最近では多次元土/水連成弾(粘)塑性有限要素解析のアプローチから,荷重履歴の違いにより土構造物の品質が異なることが報告されている.本報告では簡単な地盤モデルを想定し,二次元土/水連成弾・粘塑性有限要素解析を用いて荷重履歴の違いがもたらす過剰間隙水圧の発生形態に重点を置き,土構造物の設計において考慮すべき事項について再認識を行った.荷重履歴の違いよる過剰間隙水圧の発生
Oral presentation
- 第38回地盤工学研究発表会 (講演集 CD-ROM143 pp.285-286）, Jul. 2003, English, 地盤工学会, The FEM program for stress-deformation analysis considering non-smooth yield surface of constitutive model was developed. The consideration and handling for the singular point on non-smooth yield surface of the Sekiguchi-Ohta model was carried out based on Koiter′s associated flow rule. The extra implementation for solving the difficulty at the singular point is added to FEM program called DACSAR (without any modification to the whole procedure). The numerical results from this program with and without the extra implementation was compared.FEM for the Sekiguchi-Ohta Model considering non-smooth yield surface
Oral presentation
- 第38回地盤工学研究発表会 (講演集 CD-ROM563 pp.1125-1126）, Jul. 2003, Japanese, 地盤工学会, A hypothesis of associated flow has been generally applied to elastoplastic constitutive equations for determining irreversible plastic flow emerged in an outward normal direction to yield loci. However, some of plasticity models possess intersection corners, leading to the difficulty to determine plastic flow. This paper concerned the implementation to accommodate the problem encountered to Mohr-Coulomb model using evolution of flow rule extended by Koiter (1953, 1960) and the general approach advocated in Simo, Kennedy and Govindjee (1988). Consequently, the incremental plastic strain and stress vectors can be evaluated.Consistent tangential tensor in regard to rate-independent Sekiguchi-Ohta model
Oral presentation
- 第38回地盤工学研究発表会 (講演集 CD-ROM142 pp.283-284）, Jul. 2003, Japanese, 地盤工学会地盤材料の構造の劣化と異方化/等方化を考慮した弾塑性構成モデルの開発
Oral presentation
- 地盤工学研究発表会発表講演集, 06 Jun. 2003, JapaneseMises規準から見た境界非排水粘土供試体の破壊シミュレーション―Mises規準かMohr‐Coulomb規準か―
- 第37回地盤工学研究発表会 (講演集 CD-ROM164 pp.325-326）, Jul. 2002, Japanese, 地盤工学会回転硬化を導入した下負荷面関口・太田モデルによるKo値の算出
Oral presentation
- 第37回地盤工学研究発表会 (講演集 CD-ROM512 pp.1017-1018）, Jul. 2002, Japanese, 地盤工学会互層地盤からなる土留め掘削の変形に対する2次元FEM解析の適用例
Oral presentation
- 第37回地盤工学研究発表会(講演集 CD-ROM165 pp.327-328）, Jul. 2002, Japanese, 地盤工学会Stress Probe Testから得られる降伏曲面の解析的解釈
Oral presentation
- 第37回地盤工学研究発表会 (講演集 CD-ROM383 pp.761-762）, Jul. 2002, English, 地盤工学会Application of Dilatancy Models with Subloading Surface to Soils Reinforced by Geosynthetics
Oral presentation
- 第37回地盤工学研究発表会 (講演集 CD-ROM947 pp.1885-1886）, Jul. 2002, Japanese, 地盤工学会土/水連成弾塑性動的有限要素解析手法の開発
Oral presentation
- 第37回地盤工学研究発表会 (講演集 CD-ROM484 pp.961-962）, Jul. 2002, Japanese, 地盤工学会施工過程の違いによる人工島の品質への影響
Oral presentation
- 第37回地盤工学研究発表会 (講演集 CD-ROM167 pp.331-332）, Jul. 2002, Japanese, 地盤工学会関口・太田モデルに適用する陰解法応力更新アルゴリズム
Oral presentation
- 第37回地盤工学研究発表会(講演集 CD-ROM125 pp.247-248）, Jul. 2002, Japanese, 地盤工学会せん断に伴う応力－塑性ひずみ増分の非共軸性
Oral presentation
- 第37回地盤工学研究発表会 (講演集 CD-ROM177 pp.351-352）, Jul. 2002, English, 地盤工学会Interpretation of Koiter's associated flow rule to the corner of the Sekiguchi-Ohta model
Oral presentation
- 第37回地盤工学研究発表会 (講演集 CD-ROM166 pp.329-330）, Jul. 2002, Japanese, 地盤工学会Consistent tangential moduli for rate-independent Sekiguchi-Ohta model
Oral presentation
- 第51回理論応用力学講演会 (講演論文集（NCTAM2002）pp.211-212), Jan. 2002, Japanese, JSPS日本学術振興会メカニクス・構造研究連絡委員会異方性地盤材料の構成モデルの陰解法有限要素解析への適用
Oral presentation
- 第57回土木学会年次学術講演会(講演概要集 III部門 pp.703-704), 2002, Japanese, 土木学会締固め土における圧密降伏応力の推定
Oral presentation
- 第56回年次学術講演会 (講演概要集 III部門 pp.682-683), Oct. 2001, English, 土木学会The vertex singularity in the Sekiguchi-Ohta model
Oral presentation
- 第36回地盤工学研究発表会 (講演集 pp.2073-2074), Jun. 2001, Japanese, 地盤工学会補強工法盛土における弾・塑性解析の適用性
Oral presentation
- 第36回地盤工学研究発表会 (発表講演集 pp.937-938), Jun. 2001, Japanese, 地盤工学会関口・太田モデルによる有効内部摩擦角とＫ0値の関係
Oral presentation
- 第36回地盤工学研究発表会(講演集 pp.935-936), Jun. 2001, Japanese, 地盤工学会塑性ポテンシャル関数の尖り点における関連流則の処理
Oral presentation
- 第36回地盤工学研究発表会 (講演集 pp.897-898), 2001, Japanese, 地盤工学会中央遮水壁型ロックフィルダムの築堤および湛水シミュレーション
Oral presentation
- 平成13年度土木学会関西支部年次学術講演会 III-25, 2001, Japanese, 土木学会関西支部関口・太田による弾塑性構成モデルへの下負荷面の導入
Oral presentation
- 平成13年度土木学会関西支部年次学術講演会 III-20, 2001, Japanese, 土木学会関西支部仮想ロックフィルダムの築堤・湛水シミュレーション
Oral presentation
- 第55回年次学術講演会 (講演概要集 III部門-B184 pp.366-367), Sep. 2000, Japanese, 土木学会有限要素法を用いた掘削工事における周辺地盤変形の影響範囲の検証
Oral presentation
- 第55回年次学術講演会 (講演概要集 III部門-B309 pp.616-617), Sep. 2000, Japanese, 土木学会ジオシンセティックスによる補強効果と有限要素シミュレーション
Oral presentation
- 第35回地盤工学研究発表会 (講演集 pp.1283-1284), Jun. 2000, Japanese, 地盤工学会締固め土の圧縮特性に及ぼす供試体作成条件の影響
Oral presentation
- 第35回地盤工学研究発表会 (講演集 pp.1337-1338), Jun. 2000, Japanese, 地盤工学会掘削工事の現場計測データに基づく周辺地盤変形の影響範囲の予測
Oral presentation
- 平成12年度土木学会関西支部年次学術講演会(講演概要集 pp.III-69-1-III-69-2), Jun. 2000, Japanese, 土木学会関西支部ジオシンセティックス補強土遠心実験の有限要素解析
Oral presentation
- 第34回地盤工学研究発表会 (講演集 pp.749-750), Jul. 1999, Japanese, 地盤工学会間隙水分布を考慮した不飽和土の土／水連成解析
Oral presentation
- 第34回地盤工学研究発表会 (講演集 pp.747-748), Jul. 1999, Japanese, 地盤工学会不飽和土の応力～ひずみ関係の定式化
Oral presentation
- 第34回地盤工学研究発表会 (講演集 pp.595-596), Jul. 1999, Japanese, 地盤工学会塑性論的粘塑性論による関口・太田モデルの解釈
Oral presentation
- 第34回地盤工学研究発表会 (講演集 pp.1073-1074 ), Jul. 1999, Japanese, 地盤工学会柴山潟干拓地における道路盛土施工沈下予測
Oral presentation
- 第34回地盤工学研究発表会 (講演集 pp.791-792), Jul. 1999, Japanese, 地盤工学会ジオシンセティックスによる拘束効果―有限要素シミュレーション―
Oral presentation
- 第34回地盤工学研究発表会 (講演集 pp.789-790), Jul. 1999, Japanese, 地盤工学会ジオシンセティックスによる拘束効果―モデル実験―
Oral presentation
- 第34回地盤工学研究発表会 (講演集 pp.787-788), Jul. 1999, Japanese, 地盤工学会ジオシンセティックスで補強した盛土の変形解析パラメータの決定
Oral presentation
- 第34回地盤工学研究発表会(講演集 pp.793-794), Jul. 1999, Japanese, 地盤工学会ジオシンセティックスで補強した砂梁の有限要素シミュレーション
Oral presentation
- 第34回地盤工学研究発表会(講演集 pp.1629-1630), Jul. 1999, Japanese, 地盤工学会FEMを用いた軟弱地盤の掘削解析
Oral presentation
- 平成11年度土木学会関西支部年次学術講演会講 (演概要 III-33—1-III-33-2), May 1999, Japanese, 土木学会関西支部干拓軟弱地盤を対象とした変形解析
Oral presentation
- 第33回地盤工学研究発表会 (講演集 pp.641-642), Jul. 1998, Japanese, 地盤工学会粘性土の局所変形モードの遷移と間隙水のマイグレーション
Oral presentation
- 第33回地盤工学研究発表会 (講演集 pp.621-622), Jul. 1998, Japanese, 地盤工学会関口・太田モデルの粘塑性項の構造
Oral presentation
- 平成10年度土木学会関西支部年次学術講演会 (講演概要 III-60-1-III-60-2), May 1998, Japanese, 土木学会関西支部干拓軟弱地盤の変形解析パラメータの決定
Oral presentation
- 土木学会第52回年次学術講演会 (概要集 III部門 pp.416-417), Sep. 1997, Japanese, 土木学会弾・粘塑性変形予測解析における基準時間の影響
Oral presentation
- 第32回地盤工学会研究発表会 (講演集 pp.539-540), Jul. 1997, Japanese, 地盤工学会軟弱海成粘土のレラクゼーション特性
Oral presentation
- 第32回地盤工学研究発表会 (講演集 pp.603-604), Jul. 1997, Japanese, 地盤工学会同一現場における1軸強度,ベーン強度および等体積一面強度の整合性
Oral presentation
- 第32回地盤工学研究発表会 (講演集 pp.541-542), Jul. 1997, Japanese, 地盤工学会等体積一面せん断強度の時間依存性
Oral presentation
- 第32回地盤工学研究発表会 (講演集 pp.553-554), Jul. 1997, Japanese, 地盤工学会土/水連成有限変形FEMを用いた粘性土の破壊シミュレーション
Oral presentation
- 第32回地盤工学研究発表会 (講演集 pp.435-436), Jul. 1997, Japanese, 地盤工学会静止土圧係数の時間依存性
Oral presentation
- 土木学会第51回年次学術講演会(概要集 III部門 pp.486-487), Sep. 1996, Japanese, 土木学会有限要素解析結果を用いた限界盛土高さ推定法
Oral presentation
- Proc. 51st Annual Meeting of JSCE, Sep. 1996, EnglishNumerical simulation of in-situ pressuremeter test
Oral presentation
- 第31回地盤工学研究発表会(講演集 pp.853-854), Jul. 1996, Japanese, 地盤工学会等体積一面せん断強度の時間依存性
Oral presentation
- 第31回地盤工学研究発表会(講演集 pp.793-794), Jul. 1996, Japanese, 地盤工学会弾塑性構成モデルを用いたすべり面の発生予測
Oral presentation
- 第31回地盤工学研究発表会(講演集 pp.791-792), Jul. 1996, Japanese, 地盤工学会客観的応力速度を用いた弾・塑性体の単純せん断時の挙動
- 第31回地盤工学研究発表会(講演集 pp.2455-2456), Jul. 1996, Japanese, 地盤工学会せん断に伴う体積膨張を考慮した有限要素解析
Oral presentation
- 第31回地盤工学研究発表会(講演集 pp.2453-2454), Jul. 1996, Japanese, 地盤工学会ジオシンセティックス補強盛土の変形パラメータの決定
Oral presentation
- 第31回地盤工学研究発表会(講演集 pp.2457-2458), Jul. 1996, Japanese, 地盤工学会ジオシンセティックスの拘束効果を考慮した砂梁の有限要素解析
Oral presentation
- 土木学会第50回年次学術講演会講演（概要集 III部門 pp.402-403）, Sep. 1995, Japanese, 土木学会等体積一面せん断強度に及ぼすせん断速度と圧密時間の影響
Oral presentation
- 土木学会第50回年次学術講演会講演（演概要集 III部門 pp.728-729）, Sep. 1995, Japanese, 土木学会仮想粘性法アルゴリズムの検討
Oral presentation
- 第30回地盤工学研究発表会（講演集 pp.1209-1212）, Jul. 1995, Japanese, 地盤工学会都市型CASESタンクの周辺軟岩安定性に関する数値解析
Oral presentation
- 第30回地盤工学研究発表会（講演集 pp.1261-1263）, Jul. 1995, Japanese, 地盤工学会変形及び安定解析に用いる有限要素の選択
Oral presentation
- 第30回地盤工学研究発表会（講演集 pp.671-674）, Jul. 1995, Japanese, 地盤工学会弾塑性体の負荷基準
Oral presentation
- 第30回地盤工学研究発表会 (講演集 pp.675-678), Jul. 1995, Japanese, 地盤工学会間隙水の移動が平面ひずみ三軸圧縮せん断強度に及ぼす影響
Oral presentation
- 土木学会第49回年次学術講演会講演 (概要集 III部門 pp.848-849), Sep. 1994, Japanese, 土木学会3次元土／水練成FEMにおける離散化の仕様と計算精度の比較
Oral presentation
- 土木学会第49回年次学術講演会講演 (概要集 III部門 pp.1692-1693), Sep. 1994, Japanese, 土木学会ジオシンセティックスを埋め込んだ逆斜面盛土の現場実験
Oral presentation
- 第29回土質工学研究発表会 (講演集 pp.311-314), Jun. 1994, Japanese, 土質工学会Ｋo圧密中に作用する摩擦の評価
Oral presentation
- 第29回土質工学研究発表会 (講演集 pp.1319-1322), Jun. 1994, Japanese, 土質工学会河北潟軟弱地盤の盛土による変形解析
Oral presentation
- 第48回年次学術講演会講演 (概要集 III部門 pp.1386-1387), Sep. 1993, Japanese, 土木学会円筒形の掘削工事における非軸対称荷重の影響
Oral presentation
- 土木学会第48回年次学術講演会 (概要集 III部門 pp.934-935), Sep. 1993, Japanese, 土木学会三次元土/水連成解析によるベーン試験のシミュレーション
Oral presentation
- 第28回土質工学研究発表会 (講演集 pp.2495-2498), Jun. 1993, Japanese, 土質工学会ジオテキスタイルで補強された砂質地盤の変形解析
Oral presentation
- 第28回土質工学研究発表会 （講演集 pp.1467-1470）, Jun. 1993, Japanese, 土質工学会過去の水位変動を考慮した初期応力状態の評価－（その2）一次元ＦＥＭ解析－
Oral presentation
- 第28回土質工学研究発表会（講演集 pp.1463-1466）, Jun. 1993, Japanese, 土質工学会過去の水位変動を考慮した初期応力状態の評価―（その1）パラメータの決定―
Oral presentation
- 第28回土質工学研究発表会（講演集 pp.789-792）, Jun. 1993, Japanese, 土質工学会自然堆積粘土の強度異方性とベーン試験の解釈（その2）
Oral presentation
- 第28回土質工学研究発表会（講演集 pp.785-788）, Jun. 1993, Japanese, 土質工学会自然堆積粘土の強度異方性とベーン試験の解釈（その1）
Oral presentation
- Proc. 46th Annual Meeting of JSCE（Division-III pp.574-575）, Sep. 1992, English, JSCEFE analyses of a trial embankment on soft Bangkok clay
Oral presentation
- 第27回土質工学研究発表会（講演集 pp.1809-1812）, Jun. 1992, Japanese, 土質工学会軟弱地盤内の改良体がリバウンド挙動に与える影響
Oral presentation
- 第27回土質工学研究発表会（講演集 pp.1343-1346）, Jun. 1992, Japanese, 土質工学会土/水連性問題の離散化理論について
Oral presentation
- 第27回土質工学研究発表会 （講演集 pp.673-676）, Jun. 1992, Japanese, 土質工学会中実および中空円筒供試体に発生するすべり線について
Oral presentation
- 第27回土質工学研究発表会 （講演集 pp.665-668）, Jun. 1992, Japanese, 土質工学会せん断帯生成シミュレーションにおける有限要素の選択について
Oral presentation
- 第27回土質工学研究発表会 （講演集 pp.669-672）, Jun. 1992, Japanese, 土質工学会Ko圧密履歴を受けたハダカ中空円筒供試体のせん断試験
- 土木学会第46回年次学術講演会講演 (概要集 III部門 pp.410-411), Sep. 1991, Japanese, 土木学会盛土施工に伴う海成粘土地盤の変形解析
Oral presentation
- 第26回土質工学研究発表会 (講演集 pp.571-574), Jul. 1991, Japanese, 土質工学会平面ひずみせん断試験における端面摩擦の影響について－三次元土/水弾・粘塑性連成解析－
- 第25回土質工学研究発表会 (講演集 pp.1185-1188), Jun. 1990, Japanese, 土質工学会地盤の変形解析におけるメッシュ・フォーメーションの解析精度に及ぼす影響
Oral presentation
- 第25回土質工学研究発表会 (講演集 pp.1189-1190), Jun. 1990, Japanese, 土質工学会弱形式表現に基づいた土/水連成FEM解析手法について
Oral presentation
- 第25回土質工学研究発表会 (講演集 pp.1231-1234), Jun. 1990, Japanese, 土質工学会ひずみ軟化を示す地盤の安定と変形の解析手法
Oral presentation
- 第25回土質工学研究発表会 (講演集 pp.659-662), Jun. 1990, Japanese, 土質工学会ひずみ硬化弾塑性モデルによる極限状態－ひずみ軟化現象の可能性－
- 土木学会第44回年次学術講演会 (概要集 III部門 pp.4-5), Sep. 1989, Japanese, 土木学会軟弱地盤の変形履歴―小さな道路盛土の建設事例―
Oral presentation
- 土木学会第44回年次学術講演会 (概要集 III部門 pp.970-971), Sep. 1989, Japanese, 土木学会3次元弾粘塑性連成有限要素プログラムの開発
Oral presentation
- Proc. of Annual Conference on Soil Mechanics and Foundation Engineering( pp.343-346), Jun. 1989, English, JSSMFEIdentification of elasto-viscoplastic constitutive parameters for undisturbed sand (Omma sandstone member)
Oral presentation
- 第24回土質工学研究発表会(講演集 pp.1123-1126), Jun. 1989, Japanese, 土質工学会軟弱地盤挙動に及ぼす過去の圧密履歴の影響について
Oral presentation
- 第24回土質工学研究発表会 (講演集 pp.1233-1236), Jun. 1989, Japanese, 土質工学会盛土施工における限界盛土高さの簡易推定法
Oral presentation
- 第24回土質工学研究発表会 (講演集 pp.1463-1467), Jun. 1989, Japanese, 土質工学会山留め設計専用のFEMプログラム
Oral presentation
- 土木学会第43回年次学術講演会 (概要集 III部門 pp.508-509), Sep. 1988, Japanese, 土木学会地盤改良を伴う掘削工事の挙動解析
Oral presentation
- 第23回土質工学研究発表会 (講演集 pp.1265-1268), Jun. 1988, Japanese, 土質工学会非共軸Cam-clayモデルによるせん断帯の生成―有限要素解析―
Oral presentation
- 第23回土質工学研究発表会 (講演集 pp.1261-1264), Jun. 1988, Japanese, 土質工学会非共軸Cam-clayモデルによるせん断帯の生成―基礎理論―
Oral presentation
- 第22回土質工学研究発表会 (概要集 pp.1113-1116), Jun. 1987, Japanese, 土質工学会弾塑性変形・浸透流連成解析法による地盤の極限解析
Oral presentation
- 第22回土質工学研究発表会 (講演集 pp.1101-1104), Jun. 1987, Japanese, 土質工学会有限要素法による異方圧密地盤の極限支持力
Oral presentation
- 第22回土質工学研究発表会 (講演集 pp.1043-1046), Jun. 1987, Japanese, 土質工学会変形解析用物性パラメータの検討
Oral presentation
- 土木学会第41回年次学術講演会 (概要集 III部門 pp.319-320), Sep. 1986, Japanese, 土木学会軟弱地盤の弾・粘塑性FEM解析（その2）
Oral presentation
- 土木学会第41回年次学術講演会(概要集 III部門 pp.317-318), Sep. 1986, Japanese, 土木学会軟弱地盤の弾・粘塑性FEM解析（その1）
Oral presentation
- 第21回土質工学研究発表会 (講演集 pp.1753-1756), Jun. 1986, Japanese, 土質工学会締固め土の弾塑性構成パラメータ
Oral presentation
- 第21回土質工学研究発表会 (講演集 pp.407-410), Jun. 1986, Japanese, 土質工学会原位置べーン強度の安定解析への適用について
Oral presentation
- 第21回土質工学研究発表会 (講演集 pp.411-414), Jun. 1986, Japanese, 土質工学会プレッシャーメータ周辺要素の経験する応力経路
Oral presentation
- 第21回土質工学研究発表会(講演集 pp.415-418), Jun. 1986, Japanese, 土質工学会プレッシャーメータ試験による強度の異方性と時間依存性の解析
Oral presentation
- 土木学会第40回年次学術講演会 (概要集 III部門 pp.469-470), Sep. 1985, Japanese, 土木学会弾粘塑性有限要素解析における応力状態の把握に関する一考察
Oral presentation
- 土木学会40回年次学術講演会 (概要集 III部門 pp.395-396), Sep. 1985, Japanese, 土木学会弾粘塑性構成式を用いた有限要素解析のアルゴリズムについて
Oral presentation
- 第20回土質工学研究発表会 (講演集 pp.973-974), Jun. 1985, Japanese, 土質工学会弾粘塑性有限要素解析における入力パラメータの決定法
Oral presentation
- 第20回土質工学研究発表会 (講演集 pp.389-392), Jun. 1985, Japanese, 土質工学会弾塑性構成式を用いた非排水応力―ひずみ関係と割線変形係数
Oral presentation
- 土木学会第39回年次学術講演会 (概要集 III部門 pp.183-184), Sep. 1984, Japanese, 土木学会同一地盤上の２つの盛土の変形解析結果とその問題点
Oral presentation
- 土木学会第39回年次学術講演会 (概要集 III部門 pp.207-208), Sep. 1984, Japanese, 土木学会正規圧密粘土の変形係数
Oral presentation
- 第19回土質工学研究発表会 (講演集 pp.863-866), Jun. 1984, Japanese, 土質工学会軟弱地盤上の盛土の変形解析
Oral presentation
- 土木学会第38回年次学術講演会 (概要集 III部門，pp.417-418), Sep. 1983, Japanese, 土木学会弾塑性構成式を用いた平面ひずみ条件下の応力～ひずみ関係について
Oral presentation
- 第18回土質工学研究発表会 (講演集 pp.391-392), Jun. 1983, Japanese, 土質工学会弾塑性構成式を用いた応力～ひずみ関係に関する一考察
Oral presentation
- 第17回土質工学研究発表会講演集第（講演集 pp.165-168）, Jun. 1982, Japanese, 土質工学会バンコク粘土上の矩形盛土の変形解析
Oral presentation
- 昭和56年度土木学会 関西支部講演会 (講演概要 III-25-1-III-25-2), May 1981, Japanese, 土木学会有限要素法による盛土基礎地盤変形解析
Oral presentation
Association Memberships
Research Projects
- 公益財団法人原子力環境整備促進・資金管理センター, 平成29年度高レベル放射性廃棄物等の地層処分に関する技術開発事業TRU廃棄物処理・処分技術高度化開発, 2017, Principal investigator【経済産業省】再冠水から化学変質に至るベントナイト緩衝材の力学挙動評価解析手法の検討
Competitive research funding
- 科学研究費補助金／基盤研究(B), Apr. 2016 - Mar. 2019
Competitive research funding
- 日本学術振興会, 科学研究費助成事業 挑戦的萌芽研究, 挑戦的萌芽研究, 神戸大学, Apr. 2016 - Mar. 2018, Principal investigator深海底デコルマ帯の固着域形成と破壊すべりの弾塑性理論
本研究では，デコルマ帯の滑り込み部表層を対象に，スメクタイトからイライトへの変質を考慮した弾塑性構成モデルを開発し，土/水連成の力学体系に組み込んだ．プレート沈み込みを想定して，せん断力を受けながらデコルマ帯が変質する場合の数値シミュレーションを行なった．変質に伴う過剰間隙水圧の発生が現れ，この過剰間隙水圧の発生は，デコルマ帯付近で観測された事実と良く整合していた．さらに，変質に伴い過圧密化することにより，せん断力を受け続けるとやがて軟化して強度が低下することが分かった．このことは，デコルマ帯で固着が生じ，ゆっくり地震が発生するメカニズムに一致する．
- 日本学術振興会, 科学研究費助成事業 基盤研究(B), 基盤研究(B), 神戸大学, Apr. 2012 - Mar. 2016, Principal investigator塩害・地盤変状発生機構シミュレーションと抑止修復技術の総合化
本研究は，塩害による沙漠化抑止と修復の技術提案を通して，地盤工学の地球環境問題への積極的な寄与を目的としている．過伐採，過放牧，塩害が沙漠化の三大要因であり，全体の約8 割を占めている．森林などの植生伐採に伴う気圏・地圏間の水循環の狂いが原因である．特に塩害による沙漠化は，地下水中の希薄な塩分が高濃度化して地表に析出することにより生じ，ユーラシア大陸などの大陸の広範囲な地域で発生している．このような塩害による沙漠化メカニズムを表現できるFE シミュレータを開発し，さらに，環境負荷の低減を可能とするPS 灰や浄水場汚泥のリサイクルによる粒状材料などを活用できる塩害抑止工法を開発した．
- 日本学術振興会, 科学研究費助成事業 基盤研究(B), 基盤研究(B), 神戸大学, Apr. 2009 - Mar. 2012, Principal investigator塩害・地盤変状発生機構の解析と環境負荷汚泥焼成物を用いた防止技術の開発
ユーラシア大陸地下には,広く岩塩層が堆積していることが知られる.地層褶曲などにより岩塩層が比較的地表近くまで迫出している場合には,表層地下水にまで塩分が含まれていることが多い.典型的な事例をタイ東北部(内陸)に見ることができる.乾期,雨期の乾湿繰返しに伴って地表面への塩の析出と塩害に伴う農業生産の低下を引き起こしている.一方,東南アジアの国々では,製紙業から排出されるPS(ペーパースラッジ)や浄水場発生汚泥の処理は深刻な環境問題となっている.このような汚泥を1300度程度で焼くと,微細な多孔構造を持つ安定した多孔質材とすることができる.本研究課題は,タイ東北部をフィールドに,この多孔質材料を塩害防止・対策に用い,塩害防止と農耕地保全に役立てることを目的とし, 1.水収支の狂いによる塩分析出シミュレータの高度化, 2.タイ東北部で計測された塩害,地盤変状の解析, 3. PS焼成材,浄水場排出焼成材の力学特性の把握, 4.塩害防止,農耕地保全の構造体の提案を行った.
- 科学研究費補助金／基盤研究(A), 2007
Competitive research funding
- 日本学術振興会, 科学研究費助成事業 基盤研究(B), 基盤研究(B), 神戸大学, Apr. 2006 - Mar. 2009, Principal investigator塩害に伴う地盤変状シミュレーション技術の開発とその低減・修復策の検討
本研究は, 塩害に伴う地盤変状をシミュレートする飽和/不飽和土・水・移流拡散連成有限要素解析手法の開発とそれを用いた塩害軽減・修復技術の開発を目的としている. 多くの「塩害→植生枯死→砂漠化」の地盤環境変状・地盤環境崩壊プロセスは, 「森林の伐採」などによって, 降雨などの供給水量と植生からの蒸散水量と地表からの蒸発水量のバランスが崩れ, 塩害をもたらすと説明されてきた. 一旦, 地表面付近に塩分が析出すると, もはや少種の草木を除いて, 植生は育成することができず, さらなる地盤の乾燥化を招き, 砂漠化に至る. しかしながら, 世界の多くの地で問題視される「塩害」は, このような単純なプロセス(一次的塩害)では収まりきらない. 森林伐採は人類の生活圏の拡大に伴って生じる. 例えば, タイの場合, 新たな水田の確保のために森林が伐採された. 水田への農業用水の供給は, ため池などの地上水からの供給ばかりでなく, 地下水の汲み上げによっても補われている. 降雨の少ない乾燥地ほど地下水への依存度は高い. 地下水には, もともと希薄であったにせよ, 塩分が含まれている. 地下水への塩分の溶解は, その上流部もしくは地中深部に存在する塩岩層に起因していることが多い. 塩分を含んだ地下水を地表に汲み上げることにより, 乾季における蒸発によって塩分濃度が上昇し, さらなる塩害をもたらす. また灌漑水路などの建設は, 塩分含有地中水の濃度上昇をもたらし, これまた塩害を引き起こす(二次的塩害). 一方, 地下水の汲み上げは, 地盤変状をもたらし, 農地の機能損失, 道路の沈下・陥没などとして現われる. すなわち, 塩害の発生と,水路や道路の建設などの人為的力学作用との相互作用が重要となる. この目的を遂行するため,(1) 飽和・不飽和状態にある土の透水・力学特性,(2) 植生を介しての蒸散などの水循環, (3) 降雨による水供給と地表面蒸発などの水循環,(4) 地中水に含有している塩分などの移流拡散,(5) 地盤の変形・応力・浸透を考慮した数理モデルを組み立てた. この数理モデルのキャリブレーションを行うために, タイのカセサート大学の協力を得て, 平成18年11月27日に, バンコクでワークショップを開催した. さらに, タイ東北部のサコナコン, ウドンタニにて, 地表塩分渡度の現地測定を行った.さらに,(6) 本研究で開発した数値シミュレータを用いて, 塩害地盤の代表的な修復法であるフラッシングの効果を定量的に検討できる手法を開発し,(7) 塩害防止策として, 粗粒材料を用いたマルティング法およびパイリング法を考案した.
- 2006安全と共生のための都市空間デザイン戦略
Competitive research funding
- 2005安全と共生のための都市空間デザイン戦略
Competitive research funding
- 日本学術振興会, 科学研究費助成事業 基盤研究(C), 基盤研究(C), 神戸大学, Apr. 2003 - Mar. 2005, Principal investigator不飽和土構造物における最適補強効果の同定と経年品質変化の予測
土構造物に対する補強とは,剛な固定端で反力をとって土構造物を支えようとする機構ではない.土と補強材が一体となって剛性や耐荷力が向上しているメカニズムである.では,その力学的相互作用がどのように土構造物の剛性や耐荷力の向上に結びついているのであろうか.本研究では,土のダイレタンシー変形を補強材が拘束するメカニズムがポイントであると考えた.しかも不飽和状態におかれている土を考えねばならない.土構造物に荷重が作用する.土はせん断変形しようとするが,ダイレタンシー特性により体積膨張変形を生じようとする.この体積膨張変形を補強材が拘束することにより,土全体の剛性と強度が増し,補強効果が発現すると考えている.もしそうだとすると,土の締固め度合い(または地盤の過圧密度合い)と補強材の剛性との間に,最適な組み合わせがありうるはずである.さらに,最適な補強材の配置が見出されるはずである.本研究は,締固め土(不飽和土)を対象に,まず,1)ダイレタンシー拘束による補強効果発現メカニズムを検証し,2)ダイレタンシー特性を決定する最大締固め荷重(過圧密度合い)の推定法を提案した.これらの成果を組み込んだ数理モデル(有限要素解析手法)を開発した.これにより補強効果の定量化が可能となる.そして,3)補強材の最適な剛性,配置,量の算定を可能とし,4)最終的には,杜会ニーズに応えるべく,補強された土構造物の経年的機能変化,品質変化を予測できる手法としてまとめあげられている.
- 日本学術振興会, 科学研究費助成事業 基盤研究(C), 基盤研究(C), 神戸大学, Apr. 2000 - Mar. 2002, Principal investigator補強材によるダイレタンシー拘束効果と地盤/土構造物の補強効果評価
基礎地盤もしくは土構造物内に補強材を敷設して,土構造物の剛性や強度を増加せしめようとする補強土工法のアイデアは,古くから土木技術の一つの要であった.多くの土構造物は多種多様な補強土工法の恩恵の上に,機能を持続し続けている.しかし昨今の社会ニーズは,新規構造物の建設から既設構造物の維持・補修に移りつつある.過去に土構造物が受けた履歴と無関係に,その構造物のグローバルな安定に寄与する形にまとめあげられている現行設計法では対処しづらいケースが増えつつある.構造物の部分的なリニューアル,機能更新が求められるからである.本研究課題はこのような社会ニーズに合理的に答えうる技術体系の確立を目的とした.また,層状に敷設されたジオシンセティックス,基礎の底面端部に付けられたスカート,テールアルメの定着帯,盛土底部横断方法に設置された松杭連結の梯子,松杭,砂杭や摩擦杭,…これらが立派に地盤を補強して(地盤の力学特性の改良=地盤改良に寄与して)機能していることは,経験で知ってはいても理屈がついてこない.構造物のグローバルな安定を考える現行設計法の限界である.これらの「経験」に「理屈」を提供しようとしているとも言える.土構造物に対する補強とは,剛な固定端で反力をとって土構造物を支えようとする機構ではない.土と補強材が一体となって剛性や耐荷力が向上しているメカニズムである.では,その力学的相互作用がどのように土構造物の剛性や耐荷力の向上に結びついているのであろうか.本研究では,土のダイレタンシー変形を補強材が拘束するメカニズムがポイントであると考えた.土構造物に荷重が作用する.その荷重によって土はせん断変形を生じようとするが,土はダイレタンシー特性を有するため,同時に体積膨張を生じようとする.この体積膨張を補強材が拘束することにより,土の剛性と強度が増し,補強効果が発現する.これを室内試験,模型実験,数値解析により検証し,その発現メカニズムを明らかにした.このような補強効果は,土自身の材料特性ばかりでなく,その土の締固め度合い,含水状態などによって変化すると考えられる.そこで本研究では,不飽和状態にある土の力学特性,特に締固め度合いや含水状態の影響を,一連の室内三軸試験を実施して議論している.この成果は,新しい水分特性曲線モデルの提案に結びついた.さらに,土構造物の品質を評価する解析手法を開発し,実際の土構造物の品質評価への適用性を検討している.以上の成果を,順次,学会論文集や国際会議などに発表していった.
- 日本学術振興会, 科学研究費助成事業 基盤研究(C), 基盤研究(C), 神戸大学, Apr. 1998 - Mar. 2000, Principal investigator粘性土におけるダイレタンシーの局所化と供試体の破壊
地盤材料は少なくとも土と間隙水との混合体であって,両者の力学的な相互作用の考慮が重要である.せん断帯の生成のみを追跡していたのでは地盤材料の破壊を説明することはできない.土供試体の破壊形態はせん断速度か異なる.供試体内ひずみの局所化は,土と間隙水との相互作用の発現の仕方に左右されて,せん断が進むにつれて,「はじめほとんど均質場→ひずみが局所化→局所的に体積膨張→吸水軟化→強度低下」というプロセスを経ることが予見される.供試体が正規粘土であれば当然,供試体全体での平均過剰間隙水圧は正であるが,局所化変形領域では,負の過剰間隙水圧が発生する.すなわち「ダイレタンシーの局所化」の発現である.本研究は,まず,土のダイレタンシー特産を考慮できる弾塑性構成モデルを検討し,このようなダイレタンシーの局所化メカニズムに注目しながら,土供試体のせん断破壊現象を土/水連成の有限要素法を用いてシミュレーションしている.さらに,土のダイレタンシー挙動が,実際の土構造物において,どのような力学的相互作用を引き起こしているか,ジオシンセティックスのような異種材で補強された土構造物において,どのような補強効果を担っているのかを,現場実測事例と有限要素シミュレーションによって検討している.多くの人工土構造物は,間隙が水で満たされた飽和土から成らない.間隙に水ばかりでなく空気も存在する「不飽和」状態にある.このような不飽和状態におけるダイレタンシー挙動の発現メカニズムについても検討を行っている.不飽和土内部の間隙水分布の違いによって,その挙動は大きく異なることが分かった.さらには,そのような挙動を考慮できる数理モデルの開発した.
- 日本学術振興会, 科学研究費助成事業 基盤研究(C), 基盤研究(C), Apr. 1996 - Mar. 1998Quantification of non-coaxiality in constitutive relationship of clays and its application to limit equilibrium problem
本研究では,まず,正規圧密された粘性土供試体を軸圧縮せん断し,供試体内に発達するせん断帯の様子を観察した.次いで,有限変形理論に基づく土/水連成の弾塑性有限要素解析プログラムを開発し,平面ひずみ軸圧縮せん断のシミュレーションを行った.その結果,粘性土材料に発達するせん断帯は常に膨張を伴い,そのような局所変形が間隙水のマイグレーションを引き起こし,このマイグレーションがさらなるせん断帯の生成に支配的に影響を及ぼしていることがわかった.すなわち,間隙水のマイグレーションによって,せん断帯の生成モードが大きく変化する.また,供試体に発達するせん断帯の間隔には周期性がみられ,その周期性は境界条件によって変化することがわかった.通常の土質試験では,供試体の縦横比は2:1に取られることが多い.この場合,供試体が示すピーク強度は,供試体成型時の初期不整や間隙水のマイグレーションに支配されるせん断帯の生成モードの違いによらず,ほぼ一定の値をとることが明らかになり,現行の土質試験における規定を裏付けるものとなった.以上の成果は,数年前に他の研究グループによって先駆的に示された結果と符合しているが,有限要素解析手法の一層の精緻化をはかった結果,本研究では,より定量的で詳細な議論を可能としている.また,弾塑性速度場におけるせん断帯生成理論によれば,材料の構成関係における非共軸性がせん断帯の生成に強い影響を及ぼすことが明らかとなっている.従って,この非共軸性とダイレタンシーの関係も重要となる.本研究では,せん断に伴う体積変化(ダイレタンシー特性)の影響を考慮できるように,Hillに代表されるせん断帯生成理論の拡張をはかった.すなわち,ダイレタンシーを考慮して,せん断に伴って,せん断帯の幅の変化を許す理論を考えてみた.その結果,粘土材料の持つ非共軸性が,せん断帯の生成・発達に極めて強い影響を及ぼすことが予測された.
- 日本学術振興会, 科学研究費助成事業 奨励研究(A), 奨励研究(A), 金沢大学, Apr. 1994 - Mar. 1995, Principal investigator室内要素試験より得られる応力〜ひずみ曲線上の分岐点の同定と解析
本研究は,すべり線の発生のみならず,端面拘束などにより供試体が経験する非一様変形を一種の分岐現象として捉え,材料の構成関係を同定しながら,供試体が発現する強度を説明しようとするものである.得られた成果を要約すると以下のようになる. 1.有限要素法による解析を行う場合,極限状態近傍でのアワグラスモードやゼロエナジ-モードの発生は,本来の解を覆い隠してしまうため深刻な問題である.4つの4節点四角形要素を選び,それぞれの要素の固有ベクトルと固有値を調べることにより,極限状態近傍での特性を把握した. 2.供試体試験自身も境界問題であれば,材料の構成関係を陽な形で求めることはできない.そこでまず,従来の理論的フレームワークで,どこまで供試体の不均質場を追跡できるかを検討した.すなわち仮想粘性法を組み込んだ土・水連成FEプログラムを開発し,平面ひずみ状態での圧縮せん断を解析した.供試体中に発生する間隙水のマイグレーションが不均質場の形成に支配的な影響を及ぼすことがわかった.しかし,マイグレーションの影響が大きすぎて,材料の硬化則を同定するまでには至らなかった. 3.供試体が経験する分岐を順次追跡するためには有限変形理論が必要であるが,2より,さらに土・水の連成であることも不可欠である.そこで,Cam-clayモデルの硬化則を仮定した土・水連成FEプログラムを開発した. 4.1軸試験のようにハダカのままで圧縮せん断でき,かつそのときの有効応力を計測できる試験装置を用いて,Ko圧密された粘土に発生するスベリ線網を計測した.スベリ線網の間隔は離散的であり,供試体の壊れ方によって異なることがわかった.すなわち供試体の強度は,壊れ方に依存した離散的な量であることが予想される.
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Encouragement of Young Scientists (A), Grant-in-Aid for Encouragement of Young Scientists (A), Kanazawa University, Apr. 1991 - Mar. 1992, Principal investigatorせん断帯の生成による地盤のすべり現象の解明と支持力・安定問題への応用
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Encouragement of Young Scientists (A), Grant-in-Aid for Encouragement of Young Scientists (A), Kanazawa University, Apr. 1989 - Mar. 1990, Principal investigator非共軸/共軸弾塑性有限変形理論による地盤すべり現象の解明と変形・安定解析への応用
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Encouragement of Young Scientists (A), Grant-in-Aid for Encouragement of Young Scientists (A), Kyoto University, Apr. 1988 - Mar. 1989, Principal investigator非線形有限ひずみ弾塑性理論による地盤のせん断帯発生と極限支持力