红黏土在不同应力路径下的力学特性试验研究

采用应力-应变控制式三轴仪对贵阳市某基坑内的原状和重塑红黏土进行了等压固结和K₀固结条件下的增p剪切、减p剪切、等p剪切应力路径室内试验,以研究在不同应力路径下红黏土的力学特性。研究结果表明,不同应力路径下红黏土的力学特性有较大的差异,红黏土对应力路径的敏感性与其自身的结构性有很大关系,初始固结条件和应力路径对红黏土抗剪强度指标的影响主要表现在对粘聚力的影响上,而对内摩擦角的影响较小。应力路径是孔隙水压力变化特征的决定因素之一。排水条件对红黏土的变形影响较小,对其强度值影响明显。对等压固结和K₀固结剪切结果进行比较,认为其在两种固结条件下的变形和强度上均存在较大差异。

Experimental Study on Mechanical Properties of Red Clay under Different Stress Paths

The stress paths of increasing P shear, decreasing P shear and equal P shear in a foundation pit in Guiyang were studied by means of stress-strain control triaxial instrument under the condition of isobaric consolidation and K₀ consolidation. The mechanical properties of red clay under different stress paths were studied. The results show that there are great differences in the mechanical properties of red clay under different stress paths, and the sensitivity of red clay to stress paths is closely related to its own structure. The influence of initial consolidation conditions and stress paths on the shear strength of red clay is mainly on the cohesion, but the influence on the angle of internal friction is small. Stress path is one of the decisive factors of pore water pressure change. The drainage condition has little effect on the deformation of red clay and obvious influence on its strength. By comparing the shear results of isobaric consolidation and K₀ consolidation, it is concluded that there are great differences in deformation and strength between the two consolidation conditions.