不同温度下饱和软黏土应力路径试验研究

Experimental study of the stress path of saturated soft clay under different temperatures

温度对土的物理力学特性有较大影响,在等温条件下对宁波软黏土开展了增p、等p和减p剪切路径下的温控三轴试验,获得了不同温度、不同应力路径下的应力、孔压、有效应力路径等的变化规律。结果表明:土体的应力—应变特性呈现出较为明显的热硬化特征;温度越高,土体破坏时的偏应力越大,剪切产生的孔压越小,有效应力路径随温度的升高向总应力路径方向发生偏转;减p、等p、增p剪切路径下获得的剪应力峰值依次递增,增p和等p剪切路径下产生正孔压,减p剪切路径下产生负孔压,试样呈现剪胀现象。

There exists a great influence of temperature on the physical and mechanical properties of soil.Under the isothermal condition,temperature control triaxial stress path tests for an increase in p,a constant p and a reduction in p are carried out for the Ningbo soft clay,and changes in stress,pore pressure and effective stress path are obtained at different temperatures and under different stress paths. The results show that the stress-strain characteristics of soil show obvious thermal hardening characteristics. The higher the temperature is,the larger the deviatoric stress caused by the failure of the soil and the smaller the pore pressure. The effective stress path deflects to the direction of the total stress path with the increasing temperature. The peak of shear stress increases gradually by a reduction in p,a constant p and an increase in p. There occurs positive pore pressure in the case of an increase in p and a constant p. A negative pore pressure in the shear paths of a reduction in p,the sample shows a dilatancy phenomenon.