| Project/Area Number |
09650548
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Geotechnical engineering
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| Research Institution | Nagoya Institute of Technology |
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Principal Investigator |
MATSUOKA Hajime Nagoya Institute of Technology, Faculty of Engineering, Professor, 工学部, 教授 (90027277)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Shuichi Obayashi Corporation, Institute of Technology, Research Engineer, 技術研究所, 研究員
YOSHIMURA Yuji Gifu National College of Technology, Dept.of Civil Eng., Assoc.Prof., 助教授 (30182827)
SUN De'an Nagoya Institute of Technology, Venture Business Lab, Lecturer, ベンチャービジネスラボ, 非常勤講師 (40262951)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1998: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1997: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Yield surface / Fabric / yield criterion / Constitutive Equation / Stress history / General stress / Elastoplasic model / Granular material / 3次元 / 粒子接点角分布 |
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| Research Abstract |
1) The yield surface of granular materials determined by the fabric
Almost all yield surface of granular materials have been determined phenomenologically by the experimental results. In this study, however, the yield surface of granular materials is proposed on the basis of the microscopic fabric which is evaluated by the distribution of interparticle contact normal It is expressed in (siguma_y, siguma_x and tau_y) space in the case of two dimensional stress state and in general stress space in the case of three dimensional stress state. The proposed method can easily explain the yield due to the pure rotation of the principal stress axis with the values of the principal stresses unchanged.
2) Generation of elastoplastic model for granular materials
A transformed stress tensor has been proposed by comparing the shapes of the Extended Mises criterion and the SMP criterion in principal stress space. The SMP curve in the pi-plane of siguma_i is a circle and the SMP surface in the transformed principal stress space is a cone. The transformed stress tensor siguma_<ij> is applied to the Cam-clay models and the Sekiguchi-Ohta model to combine the critical state theory with the SMP criterion. The revised models, with the same soil parameters as the Cam-day models and Sekiguchi-Ohta model, are capable of predicting the drained and undrained behavior of clay in general stress conditions. Therefore, it is possible to extend any other elastoplastic models for soils, whose validity has been verified only in triaxial compression condition, to the general stress conditions by using the transformed stress tensor siguma_<ij> instead of the ordinary stress tensor siguma_<ij>. Moreover, the revised model is extended to be a unified elastoplastic model for clay and sand by introducing a new hardening parameter H, which can describe the negative and positive dilatancy characteristics of soils with the initially stress-induced anisotropy including the initial isotropy.
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