Investigation of Soil-water Coupled Behavior of Saturated Clay near/at Critical State and Its Application to Deformation and Failure Problems

饱和粘土近/临界状态的土水耦合行为研究及其在变形和破坏问题中的应用

基本信息

批准号：
06452267
负责人：
ASAOKA Akira
金额：
$ 4.1万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

In order to investigate "time dependent behavior" of normally consolidated/overconsolidated clay, triaxial compression tests and the soil-water coupled analysis employing the sub-loading surface Cam clay model have been carried out. The bifurcation analysis can explain "time dependent behavior" of clays by using pore water migration effect instead of visco-plasticity. The triaxial compression tests carried out in this research showed that : 1) Undrained creep failure occurs due to the change of 1^<st> failure mode to 2^<nd> mode of soil specimen that associated with pore water migration. 2) Overconsolidated clay exhibits progressive failure under constant loading in drained condition due to the absorbed water during testing. It took about 6 hours for the failure of overconsolidated clay specimen. The progressive failure is observed with the fluctuations of axial strain rates against axial strain.Imperfection-sensitive bifurcation of a plane strain saturated soil column with undrained b … More oundaries is investigated by soil-water coupled finite deformation analysis. An initial cosine-curve geometrical imperfection of 2nd mode is applied to the soil specimen. The linear constraint conditions, "no angle change and no direction change" are imposed over the loaded boundary. The soil is assumed to follow the sub-loading surface Cam-clay model. When the load application to the specimen is held at a point near the bifurcation point, load displacement curve starts to deviate from the main path, ultimately approaching unstable 1st mode path. This mode switching due to pore-water migration after the peak in load-displacement curve, that yield low undrained shear strength describes the undrained creep, which is traditionally attributed to visco-plasticity. Similar to the experiment, the increase in axial strain rate against axial strain in heavily overconsolidated soil specimen when the applied load is kept constant, illustrates the initiation of progressive failure due to softening in the highly sheared zones. Less

为了研究“时间依赖行为”过度固结的粘土，分叉分析可以解释“粘土的时间依赖性行为。）由于1^<st>的失败模式变化为2^<nd>的土壤样本，这与孔隙水迁移相关。轴向应变饱和的平面敏感性……由土壤 - 水耦合的有限变形分析研究在梨上保持双体弯曲点，负载显示曲线偏离主要路径，最终接近不稳定的第一次模式转换，这是由于毛孔 - 水峰值曲线峰后毛孔迁移引起的，从而产生低不足的剪切强度，描述了不液压的蠕变传统上，这归因于visco-Plastics