降雨条件下含软弱夹层土坡的离心模型试验研究

Centrifuge modeling of rainfall-induced deformation of slopes with weak layers

进行了降雨条件下含软弱夹层黏性土坡的离心模型试验。试验主要研究了降雨条件下坡体的吸力和变形规律,重点分析了软弱夹层对坡体的影响。测量了含软弱夹层黏性土坡的位移和土坡内一点的吸力。试验结果表明由于软弱夹层的遇水软化和高渗透特性,降雨后含软弱夹层黏性土坡在软弱夹层发生滑出。降雨条件下含软弱夹层黏性土坡的变形可以分为均匀变形、错动阶段和滑坡3个阶段。对降雨过程中的吸力变化与坡体应变变化进行了分析,表明可以通过坡体中各点应变的发展反推出降雨入渗时刻和分布。软弱夹层的存在造成了降雨入渗分布的变化,导致了坡体错动带在该处不再连续,并降低了边坡的稳定性。

Centrifugal model tests are conducted to investigate the behaviors of cohesive soil slopes with weak layers under rainfall condition.This study mainly focuses on the soil suction change and deformation process of the slopes.The centrifugal model tests show that failure occurs in the soil slope with a horizontal weak layer,with the slip surface passing through the weak layer.The analysis of displacement and strain of the slope shows that the deformation process of cohesive soil slopes with weak layers under rainfall consists of three stages： uniform stage,dislocation stage and failure stage.During the precipitation process,the pattern of rainfall infiltration can be determined through the strain development of specific points in the slope.The existence of the weak layer,which exhibits significant softening due to saturation and high permeability,causes change in the infiltration distribution and deformation and increases the instability of the slope.