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

提出了一个粘土的弹粘塑性模型。该模型能唯一地描述正常固结粘土在三维应力作用下各种随时间变化的变形和强度。利用t_的概念考虑了中间主应力的影响<ii>，将粘塑性应变速率分为两个分量，考虑了应力路径对粘塑性流动方向的影响。通过引入由关口发展的非定常流面理论来表示与时间相关的行为。通过三轴压缩和拉伸条件下的不排水蠕变试验、不排水应力松弛试验、不排水恒应变速率试验和部分排水剪切试验等，验证了模型的有效性，并将该模型应用于路堤地基的有限元分析。

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.