重塑红棕色玄武岩残积土的残余强度试验研究

以重塑红棕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下,土样干密度、含水率、加载方式及剪切速率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硬化型,试样的状态对其峰值强度和残余强度均有影响,且该土样的峰值强度和残余强度差值较小。相同干密度的试样在同一加载方式下,各强度指标随含水率的变化趋势近似一致。峰值强度、残余强度、内摩擦角指标都随着剪切速率的增加而明显增大,但剪切速率对凝聚力指标的影响在不同的加载方式下并不一致。

Study of residual strength test on remodeling reddish brown basalt residual soil

The multistage ring shear tests under different loading conditions were carried out on remodeling reddish brown ba-salt residual soil with different dry density and moisture content. Under large shear displacement, the effect of dry density, mois-ture content, loading conditions and shear rate on the peak strength and the residual strength are studied. The tests showed that the shear stress-displacement curves of the samples presented a strain hardening; the state of the samples can affect the peak strength and the residual strength, and the differences between the peak strength and the residual strength are small. The trends of strength indexes with the moisture content of the same dry density samples under the same loading condition are approximately consistent with each other. The peak strength, residual strength, internal friction angle increase significantly with the increase of shear rate, but the effect of shear rate on cohesion at different loading conditions are not consistent.