Constitutive models for geomaterials considering induced anisotropy and density of soils and their application, to bearing capacity problems of foundation under various loading conditions

考虑诱发各向异性和土壤密度的岩土材料本构模型及其在不同荷载条件下地基承载力问题中的应用

基本信息

批准号：
12650492
负责人：
NAKAI Teruo
金额：
$ 2.3万
依托单位：
Nagoya Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650492/
关键词：
sand clay constitutive model anisotropy density bearing capacity FEM model test モデル実験

项目摘要

New isotropic hardening and kinematic hardening elastoplastic models for sand and clay, which are named subloading tij-model and kinematic subloading tij-model respectively, are developed, referring to the previous models based on tij concept. In these models, the influence of density and confining pressure on the deformation and strength of soils are properly considered. Furthermore, Stress induced anisotropy is taken into account in the kinematic hardening model. The validity of proposed models is checked using the experimental data of triaxial compression and extension tests, true triaxial tests, plane strain tests and hollow cylinder tests on sand and clay. The results predicted by the proposed models can simulate well the stress-strain behavior and strength of sand and clay including strain softening after failure. The material parameters of these models are small in number and are not influenced by the density and confining pressure. Therefore the present models are applicable to … More the geotechnical problems in which the density of the ground materials is changed during their deformation.The constitutive models are implemented into the finite element program and applied to the analyzes of some geotechnical problems such as bearing capacity problems of shallow foundations. The behavior of shallow foundation under eccentric load, inclined loading combined loading as well as concentric loading is analyzed. The corresponding model tests of shallow foundation are also carried out with a new developed device that can impose various kinds of loads. Even though the stress levels of model tests are very low, there are good qualitative agreements between the tests results and the analytical results under various loading conditions? I.e., scale effect of bearing capacity, load settlements curves, vertical and horizontal movements of the foundation including its rotation and others. It is shown that the finite element method in which typical mechanical characteristics of geomaterial are properly taken into consideration can give realistic solutions of geotechnical problems and is a powerful tool for the practical design of geotechnics. Less

参考先前基于 tij 概念的模型，建立了新的砂和粘土各向同性硬化和运动硬化弹塑性模型，分别称为次加载 tij 模型和运动学次加载 tij 模型。此外，运动硬化模型还考虑了应力引起的各向异性。通过对砂土和粘土进行三轴压缩和拉伸试验、真三轴试验、平面应变试验和空心圆柱试验等试验数据进行检验，所提出的模型预测结果能够很好地模拟砂土和粘土的应力应变行为和强度。这些模型的材料参数数量很少，并且不受密度和围压的影响，因此适用于地面材料密度变化的岩土工程问题。他们的变形。将本构模型嵌入到有限元程序中，并应用于浅基础承载力问题等岩土工程问题，对浅基础在偏心荷载、倾斜荷载和同心荷载下的性能进行了模型试验分析。浅基础的研究也采用新开发的装置进行，该装置可以施加各种载荷，尽管模型试验的应力水平非常低，但在各种载荷条件下，试验结果与分析结果之间存在良好的定性一致性。即规模效应承载力、荷载沉降曲线、基础垂直和水平运动（包括旋转等）的结果表明，适当考虑岩土材料典型力学特性的有限元方法可以给出岩土工程问题的现实解决方案。岩土工程实用设计的强大工具。