川东红层缓倾角地层中降雨引起滑带土饱和对滑坡的稳定性影响

以四川省宣汉县天台乡滑坡为例,研究了降雨引起滑带土饱和对滑坡的稳定性影响。首先通过土工试验分别测试了天然和饱和状态下滑带土的剪切强度,结果显示滑带土饱和时的剪切强度比天然状态时下降较大;然后利用Geostudio软件对降雨条件下天台乡滑坡坡体内的渗流场进行了模拟,并分别计算坡体在上述渗流场作用下滑带土天然及饱和状态时滑坡的稳定系数,结果表明,滑带土饱和对川东红层缓倾角滑坡的稳定性影响较大,川东红层缓倾角滑坡的形成是降雨引起坡体内应力变化和滑带土强度降低共同作用的结果。

Influence of Slipped Soil on the Stability of Landslides in Eastern Sichuan Province

Currently, researches on the mechanism of landslides in red gently inclined formations in the Eastern Sichuan Prov- ince mainly focus on the change of seepage fields induced by the rainfall. This paper selects the Tiantai Landslide in Xuanhan County, Sichuan Province to study the influence of the slipped soil zone on the stability of the landslide in the area. The shear strength of the samples from the slipped soil zone of the Tiantai Landslide under both natural moisture and saturated conditions are laboratory tested. The test results show that the shear strength of saturated soil samples is significantly tess than the strength of the samples under the natural moisture conditions. The Geostudio software is used to model the seepage field change induced by rainfall. The factor of safety for slope stability is computed using shear strength of the slipped soil zones under both natural moisture and saturated moisture conditions. The computational results show that shear strength of the slipped soil has a significant influence on the stability of the landslide. The existing research indicates that the landslide occurred due to the combined effect of both the stress field change and the shear strength reduction in the slipped soil zones induced by the rainfall.