贵州重塑黄褐色玄武岩残积土残余强度试验研究

Research on Shear Strength of Guizhou Khaki Remodeling Basalt Residual Soil by Ring-shear Tests

以重塑黄褐色玄武岩残积土为研究对象,利用环剪仪对不同干密度、不同含水率的土体进行了不同加载方式下的多级环剪试验,探求了在大剪切位移条件下,土样干密度、含水率和加载方式对土体峰值强度和残余强度的影响。试验表明:试样的剪应力-剪切位移关系曲线呈应变软化型;对同一干密度土样,其峰值强度和残余强度随含水率的变化受每级固结后的状态影响较大;随着含水率的增大,残余黏聚力逐渐减小,而残余内摩擦角在较小的范围则小幅增大。对于同一含水率土样,干密度与峰值强度和残余强度均呈负相关关系,即峰值强度和残余强度均随着干密度的增大而减小。

The multistage ring shear tests under different loading methods were carried out for different dry density and moisture content of remodeling reddish tan basalt residual soil. During the large shear displacement, the effects of dry density, moisture content, loading methods and shear rate on the peak strength and the residual strength were studied. The strain soften phenomenon is founded in the experimental shear stress-displacement curves of the sam- ples. The variation of peak strength and residual strength with water content about the same dry density soil samples was significantly affected by vertical loading. The residual cohesion gradually decreases with the increasing of water content, while the residual internal friction slightly angle increases. The peak strength and residual strength of the soil samples with same water content was inversely proportional to their dry density, i.e. the peak intensity and resid- ual strength of the soil samples decreases with the increasing of dry density.