Experimental analysis on creep mechanics of unsaturated soil based on empirical model

Abstract

Abstract In order to reflect the creep characteristics of unsaturated silty clay, a triaxial compression consolidation drainage creep test was conducted under the condition of controlling the matric suction. According to the results of the creep test, combined with the empirical models, Mesri model and Log-modified model, the relationship between the initial tangent modulus and the matric suction was established, and two empirical models of unsaturated soil creep considering the effect of matric suction were constructed. The study confirmed the stress–strain through the ε/D–ε relationship curve, and determined the parameters F and n through power function. The methods for determining the strain–time relationship parameters of the two improved models are different. The improved Mesri model was obtained by fitting the ln ε–ln t relationship, while the improved Log-modified model was solved by the BFGS algorithm and the general global optimization method. By comparing the two improved models of unsaturated soil creep tests, it was found that the improved Mesri model can more accurately describe the creep characteristics of unsaturated soils, which confirms the rationality and feasibility of this model and method.