重塑膨胀土直剪试验中的应力-应变曲线特性

通过不同干密度、不同初始含水率在施加不同压力下的重塑膨胀土的直剪试验,研究了南(宁)-友(谊关)路膨胀的应力-应变特性以及强度指标的变化情况。研究表明:干密度的增加能大幅提高土体的峰值强度,但对残余强度影响不大,土体的粘聚力与干密度成良好的指数关系,内摩擦角受干密度影响较小;随初始含水率增加,膨胀土体峰值强度的剪切位移增加,而峰值强度、粘聚力、内摩擦角有先增大后减小的趋势;垂直压力的增大对提高重塑膨胀土峰值强度和残余强度都有一定帮助。

Characteristics of stress-strain relation of remolded expansive soils in direct shear test

The direct shear tests of remolded expansive soils were performed for different dry densities and original water content with different stresses.The stress-strain relation and strength index of Nan(ning)-You(yiguan) remolded expansivesoils was studied.Results showed that with increasing dry densities,the peak strength of soil increases significantly,but the residual strength had no significant changes.The soil cohesion had an exponential relationship with dry densities,but soils angle of internal friction had little change with dry densities.With increasing original water content,shear displacement of peak strength increases,the cohesion and soils angle of internal friction first increases,then decreases.Increasing vertical pressure had some help to both the peak strength and residual strength of the remolded expansive soils.