Elasto-viscoplastic constitutive model for clay in three-dimensional stresses and its application to practical problems.

提出了黏土的弹粘塑性模型。该模型能独特地描述正常固结粘土在三维应力作用下的各种随时间变化的变形和强度。采用t_<ii>的概念考虑了中间主应力的影响，将粘塑性应变率分成两分量考虑了应力路径对粘塑性流动方向的影响。通过引入Sekiguchi的非定常流面理论来表达其随时间变化的特性。通过不排水蠕变试验、不排水应力松弛试验、不排水恒应变率试验和部分排水剪切试验等三轴压缩拉伸试验验证了模型的有效性。并将该模型应用于路堤基础的有限元分析。

An elasto-viscoplastic model for clay is proposed. This model can describe uniquely various time-dependent deformation and strength of normally cnsolidated clay in three-dimensional stresses. The influence of intermediate principal stress is taken into consideration by using the concept of t_<ii>, and the influence of stress path on the direction of viscoplastic flow by dividing the viscoplastic strain rate into two components. The time-dependent behavioun is expressed by introducing the non-stationary flow surface theory developed by Sekiguchi. The validies of the model are checked by undrained creep tests, undrained stress relaxation rests, undrained constant strain rate tests and partially drained shear tests and others in triaxial compression and extension conditions.Further, the present model is applied to a finite element analysis of embankment foundation.