This work focuses on the uniqueness of rate-dependency, creep and stress relaxation behaviors for soft clays under one-dimensional condition. An elasto-viscoplastic model is briefly introduced based on the rate-depend...This work focuses on the uniqueness of rate-dependency, creep and stress relaxation behaviors for soft clays under one-dimensional condition. An elasto-viscoplastic model is briefly introduced based on the rate-dependency of preconsolidation pressure. By comparing the rate-dependency formulation with the creep based formulation, the relationship between rate-dependency and creep behaviors is firstly described. The rate-dependency based formulation is then extended to derive an analytical solution for the stress relaxation behavior with defining a stress relaxation coefficient. Based on this, the relationship between the rate-dependency coefficient and the stress relaxation coefficient is derived. Therefore, the uniqueness between behaviors of rate-dependency, creep and stress relaxation with their key parameters is obtained. The uniqueness is finally validated by comparing the simulated rate-dependency of preconsolidation pressure, the estimated values of secondary compression coefficient and simulations of stress relaxation tests with test results on both reconstituted Illite and Berthierville clay.展开更多
Conventional consolidation tests on reconstituted specimens of numerous natural soft clays show a decreasing of creep index Cae with increasing soil density. Based on all selected and conducted experimental results, a...Conventional consolidation tests on reconstituted specimens of numerous natural soft clays show a decreasing of creep index Cae with increasing soil density. Based on all selected and conducted experimental results, a modified creep index Cae＊ defined in double logarithmic plane lge-lgt, was plotted for various clays, from which Cae＊ can be assumed as a constant for different soil densities. Then, the modified creep index was applied to a newly developed elastic viscoplastic model. In this way, the modified creep index Ca＊ can naturally take into account the nonlinear Cae revealing the influence of soil density in the soil assemblies without additional parameters. Finally, the enhanced model was incorporated into the finite element code ABAQUS and used to simulate a consolidation test and a test embankment. The improvement of simulations by the modified creep index was highlighted by comparing simulations using the conventional creep index Cae.展开更多
基金Projects(41372285,41272317,51278449,51238009)supported by the National Natural Science Foundation of ChinaProject(20110073120012)supported by Research Fund for the Doctoral Program of Higher Education of ChinaProject(PIAPP-GA2011-286397)supported by the European Program CREEP
文摘This work focuses on the uniqueness of rate-dependency, creep and stress relaxation behaviors for soft clays under one-dimensional condition. An elasto-viscoplastic model is briefly introduced based on the rate-dependency of preconsolidation pressure. By comparing the rate-dependency formulation with the creep based formulation, the relationship between rate-dependency and creep behaviors is firstly described. The rate-dependency based formulation is then extended to derive an analytical solution for the stress relaxation behavior with defining a stress relaxation coefficient. Based on this, the relationship between the rate-dependency coefficient and the stress relaxation coefficient is derived. Therefore, the uniqueness between behaviors of rate-dependency, creep and stress relaxation with their key parameters is obtained. The uniqueness is finally validated by comparing the simulated rate-dependency of preconsolidation pressure, the estimated values of secondary compression coefficient and simulations of stress relaxation tests with test results on both reconstituted Illite and Berthierville clay.
基金Project supported by the National Natural Science Foundation of China （Nos. 41240024, 41372285, 41272317, 51278449, and 51238009）, the Research Fund for the Doctoral Program of Higher Education of China （No. 20110073120012）, and the European Project CREEP （PIAPP-GA-2011-286397）
文摘Conventional consolidation tests on reconstituted specimens of numerous natural soft clays show a decreasing of creep index Cae with increasing soil density. Based on all selected and conducted experimental results, a modified creep index Cae＊ defined in double logarithmic plane lge-lgt, was plotted for various clays, from which Cae＊ can be assumed as a constant for different soil densities. Then, the modified creep index was applied to a newly developed elastic viscoplastic model. In this way, the modified creep index Ca＊ can naturally take into account the nonlinear Cae revealing the influence of soil density in the soil assemblies without additional parameters. Finally, the enhanced model was incorporated into the finite element code ABAQUS and used to simulate a consolidation test and a test embankment. The improvement of simulations by the modified creep index was highlighted by comparing simulations using the conventional creep index Cae.
