黏土和砂土简单的三维本构模型(英文)

A simple 3-D constitutive model for both clay and sand

把修正剑桥模型推广为适合于黏土和砂土的简单、统一三维本构模型是基于以下两点提出的 :第一点 ,把由笔者已提出的基于SMP准则的一个变换应力张量用于修正剑桥模型使其简单实现了三维化 ,改进的模型对于黏土实现了从剪切屈服到剪切破坏的统一及临界状态理论同SMP准则的结合 ;第二点 ,为了建立对于黏土和砂土简单、统一的本构模型 ,推导出了一个新的硬化参数 ,新硬化参数不仅能描述砂土不同程度的剪胀性 ,对于正常固结黏土又能退化成塑性体积应变 ,所提硬化参数的合理性也被各种路径下分别在三轴压缩和三轴伸长下的试验结果所证实。所提模型的计算参数仅为 5个常规试验参数 。

A simple and unified constitutive model for both clay and sand under three dimensional stress conditions is derived from the modified Cam clay model,taking the following two points into consideration.First,a transformed stress tensor based on the SMP (Spatially Mobilized Plane) criterion is applied to the Cam clay model.The proposed model realizes the consistency from the shear yield to the shear failure and the combination of the idea of the critical state theory with the SMP criterion for clay.Secondly,a new hardening parameter is derived in order to develop a simple and unified constitutive model for both clay and sand.It can not only describe the dilatancy from lightly to heavily dilatant sand,but also be reduced to the plastic volumetric strain for clay.The validity of the hardening parameter is confirmed by the test results of triaxial compression and extension tests on sand under the various stress paths.Only five conventional soil parameters are needed in the proposed model.