Numerical implementation of a constitutive model for soil creep

Abstract

Multi-dimensional (2-D and 3-D) soil creep models creep model (Bjerrum, 1967), which is based expression for creep strain rate, and are generalized from Bjerrum’s 1-D on field test data. This model is based later modified for transient loading conditions. This differential form of 1-D creep model is extended to multi-dimensional (2-D and 3- D) state of stress and strain by incorporating concepts of visco-plasticity. on an was The devised 2- D and 3-D creep models take into account both volumetric creep strain and deviatoric defined by several material parameters. A non-linear, time incrementing finite element program, along with iterative corrections creep strain, and creep deformation of the soil is within each time step, had been already developed for research purposes by Dr. U. G. A. Puswewala (Puswewala and Rajapakse, 1992). Certain modifications were done in the latter main program to incorporate the present model as an element subroutine for plane strain condition. The numerical model will enable to check the sensitivity of model parameters on predicted results as well as the time-dependent solution of complicated foundation-soil interaction problems involving creep of soil. Numerical analyses conducted on three different soil-structure interaction configurations using published experimental data and parametric studies are conducted to evaluate the sensitivity of different input parameters of the model. The verified program will be an important resource tool for estimating settlements in structures founded on soils exhibiting creep.