泾阳南塬黄土环剪强度特性试验研究

Experiments of Shear Strength Characteristics in Ring Shear Tests of Loess from South Jingyang Plateau

研究大剪切位移条件下土的抗剪强度特性,对于边坡稳定性分析以及滑坡防治等具有重要意义。利用环剪试验仪,研究了饱和状态下泾阳南塬黄土在不同法向应力和剪切速率下的抗剪强度特性。试验结果表明:饱和黄土的抗剪强度随法向应力的增大而增大,呈明显的线性关系;随着剪切速率的增大,饱和黄土的抗剪强度呈减小的趋势;在剪切速率较低时,饱和黄土的剪应力—位移曲线呈应变硬化型,而剪切速率较高时,剪应力—位移曲线出现较明显的剪切峰值强度,表现为应变软化型,且剪应力达到峰值强度时的剪切位移也随剪切速率的增大呈增大的趋势。

Shear strength characteristics of large shear displacement of soil has important significance to the slope stability analysis and landslide prevention. Experiments were conducted on shear strength of saturated loess from South Jingyang Plateau at different normal stress and shear rate by using ring shear test. The results shows that the shear strength of saturated loess increases with the normal stress increases and reveal strong linear relationship,the shear strength of saturated loess decreases while the shear rate increases at low shear rate,shear stress- displacement curve of saturated loess shows strain hardening model,and at high shear rate,shear stress- displacement curve shows relatively obvious peak shear strength which shows the strain softening mode,and the shear displacement of shear stress at the peak time of strength also increases with the increase of shear rate.