Uniqueness of rate-dependency, creep and stress relaxation behaviors for soft clays

• Published in: Journal of Central South University Vol. 22; no. 1; pp. 296 - 302
• Main Authors: Zhu, Qi-yin, Yin, Zhen-yu, Xu, Chang-jie, Yin, Jian-hua, Xia, Xiao-he
• Format: Journal Article
• Language: English
• Published: Heidelberg Central South University 2015
• Subjects: Engineering; Metallic Materials; soft clays; creep; oedometer test; rate-dependency; stress relaxation
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-015-2521-y

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.