一种黄土滑坡渐进破坏过程分析

在中国西北，建设了许多灌溉水渠，由于水渠的灌溉引起了许多滑坡破坏，并带来了人员伤亡和财产损失。以高楼村水渠灌溉引起的黄土滑坡破坏为例，提出了滑坡破环渐进过程为：水的入渗在滑体中产生一定深度的水压力，引起黄土黏聚力和摩擦角下降，使滑坡体在一定深度产生剪破坏，紧接着滑体后缘产生拉剪破坏，致使后缘黄土处于破坏后区状态，并产生不平衡剪应力。该不平衡剪应力驱动滑体向前移动，直至滑面只有一点处于临界状态，随即整个滑坡发生破坏，并伴随着滑体解体，产生泥流。这种破坏过程可以概括为：滑坡先产生剪破坏，紧接着后缘产生拉剪破坏，当破坏后区产生的驱动剪应力大于滑体的摩阻力，会推动滑坡向前移动，直至滑坡发生完全破坏。以理论和试验论证了这种破坏机制的正确性，并验证了一种新剪应力本构模型的合理性。

Analysis of progressive failure of a loess landslide

In western China, many irrigation canals have been built to encourage the development of agriculture. At the same time, the failures of loess landslides are provoked by irrigation, and caused great loss and heavy casualties. Taking the failure of loess landslide caused by irrigation in Gaolou village channel as an example, the irrigation of the canal is proposed. The water infiltration produces a certain depth of water pressure in the sliding body, the loess cohesion decreases and the friction angle becomes smaller, which causes shear failure of the landslide body at a certain depth, and then the shearing damage occurs at the trailing edge of the sliding body, causing the trailing edge loess to be in the state of the post-destruction zone and generating unbalanced shear stress. The unbalanced shear stress drives the sliding body to move forward until only one point of the sliding surface is in a critical state, and then the entire landslide is destroyed, and the body is disintegrated to generate mudflow. This failure process can be summarized as follows: the landslide first produces shear failure, and then the trailing edge produces tensile shear failure. When the driven shear stress generated in the post-destruction zone is greater than the frictional resistance of the sliding body, it will push the landslide forward until the landslide occurs damage completely. The correctness of this failure mechanism is demonstrated by theory and experiment, and the rationality of a new shear stress constitutive model is verified.