考虑温度影响的重塑非饱和膨胀土非线性本构模型

以非饱和土的非线性模型为基础,通过对土性参数的修正和考虑温度本身引起的土的变形,建立了考虑温度效应的重塑非饱和膨胀土的本构模型。该模型包括土骨架的本构关系和水量变化的本构关系两个方面,涉及18个参数,都可用非饱和土三轴试验确定。共做了13个重塑非饱和膨胀土温控三轴试验,分析了温度对土的强度和变形的影响,研究了模型参数的变化规律。

Thermo-nonlinear model for unsaturated expansive soils

Based on the nonlinear model for unsaturated soils , a thermo-nonlinear model for unsaturated expansive soils is presented through modifying the parameters and taking account of thermal effects on deformation of soils. The model consists of two aspects, i.e. the deformation of soil skeleton and the water volume change of unsaturated soils. Total of 18 parameters are involved in this model. All the parameters can be determined using laboratory tests. A series of controlled temperature triaxial tests have been conducted; test results of reconstituted unsaturated bentonite clay are presented. The controlled temperatures are 15℃, 30℃, 45℃ and 60℃ and the thermal effects on shear strength and Young’s tangent modulus are discussed. The research results show that the specimens with higher temperatures show higher shear strengths and Young’s tangent modulus. The formulas of shear strength and Young’s tangent modulus taking account of temperature are proposed.