Dilatancy equation and generalized plastic constitutive model for coarse-grained soils
GUO Wan-li1, ZHU Jun-gao1, 2, PENG Wen-ming1, 2
1. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210098, China; 2. Key Laboratory of Failure Mechanism and Safety Control Techniques of Earth-Rock Dam of the Ministry of Water Resources, Nanjing 210024, China; 3. China Power Construction Group Chengdu Survey and Design Institute Limited, Chengdou 610072, China
Abstract：A new dilatancy equation is proposed by adding a factor to the dilatancy equation of Cambridge model, and this factor can adjust the shape of curve between the dilatancy ratio and the stress ratio for coarse-grained soils, and can reflect the nonlinear relationship. Thus a new constitutive model based on the generalized plastic theory is proposed. The main conclusions are as follows: (1) The method of determining the parameters of the proposed dilatancy equation is simple, and its capability to reflect the dilatancy properties of coarse-grained soils is verified by CD tests; (2) There are 9 parameters in this model and their definitions are clear, and the methods to determine parameters through the indoor tests are given; (3) According to the generalized plastic constitutive model, the stiffness matrix under the general stress state is deduced, and the triaxial constant p tests and two-stage constant-stress-ratio tests are carried out to verify its rationality.
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