降雨入渗对含软弱夹层堆积体滑坡的模型试验

Model Tests of Rainfall Infiltration for Landslide Deposits with Weak Layer

为揭示降雨入渗对含软弱夹层堆积体边坡稳定性的影响,通过固定式双渗透降雨物理模拟技术和光纤光栅传感器技术,对 4 种坡角的软弱夹层顺层堆积体开展了降雨物理模拟试验,测量了降雨过程中滑坡体内关键位置的位移及力学参数变化情况。结果表明,在相同降雨情况下,不同坡度的堆积体斜坡在位移和力学变化上具有相似性,降雨前后坡体的位移、土压力和水压力变化经历上升-下降两个阶段,软弱夹层位移在降雨后仍然保持蠕变;坡角越平缓的坡体后缘位移量大于坡体较陡的斜坡,而坡体前缘则反之;坡角为平缓的坡体后缘先开始形成拉裂缝,变形破坏具有渐进性、推动式的特点;而坡度越陡的坡体前缘率先破坏,变形具有突变性、牵引式特点,为滑坡防治提供了新的试验方法和手段。

In order to investigate the rainfall infiltration effect on stability of the deposit slope with weak layer rain physical model was tested on the weak layer with four different slope angles. Mechanics and deformation pa rameters of the key position in landslide deposits were studied aiming at deposits slope with weak layer under differ ent slope angles. The results show that under the same rainfall conditions the displacement and mechanical chan ges of deposit slope with different angles are similar by the variation pattern while the change of slope displace ment soil pressure and water pressure are characteristic by two stages of rising and falling but the displacement of deposit slope with weak interlayer remained creep after rainfall. In addition the displacement at the rear edge of slope with gentle angle is larger than that of steep while the front edge of slope is opposite. At the same time the more gentle angle of the slope are prone to form tensile crack in the back edge of the slope and it’s deformation and failure has the characteristics of progressive and thrust type landslide. While the front edge of the slope with a steeper slope broke first and the deformation was characterized by sudden and retrogressive landslide. Moreover with the increase of rainfall time the deposit slope with weak interlayer is characterized by the trailing edge crack ing and the leading edge bulge. It provides a new test method and means for landslide control.