典型人类工程活动诱发黄土滑坡灾害特征与致灾机理

为了揭示人类工程活动诱发的黄土滑坡成灾机理，基于典型工程活动触发黄土滑坡案例分析，采用野外调查、物理模型试验和应力路径试验等方法，分析了堆载触发黄土滑坡剪切带形成过程、卸载触发黄土滑坡演化模式和灌溉诱发黄土滑坡的成灾过程。研究结果表明:堆载和卸载触发的黄土滑坡，垂直节理易演化成裂缝带，剪应力作用下剪切蠕变带逐渐由坡脚向坡体内部扩展，直至发展成贯通的剪切带，坡体整体变形破坏，堆载触发黄土滑坡具有典型浅层、深层双滑带特征；灌溉诱发黄土滑坡主要发育在黄土塬边，长期农田灌溉导致地下水抬升，坡体内形成饱和带，重力荷载作用下发生蠕动剪切破坏，滑坡开始启动，大规模的快速覆盖加载导致坡体前部浅层黄土液化，最终触发黄土泥流远程滑坡。 

Disaster Characteristics and Destructive Mechanism of Typical Loess Landslide Cases Triggered by Human Engineering Activities

In order to reveal the mechanism of loess landslide hazards induced by human engineering activities, typical loess landslide cases were studied using field investigations, physical model tests, and stress path tests. Analyses were made for the formation of shear zones triggered by heap loading, the evolution patterns of loess landslides triggered by unloading, and the development process of loess landslides induced by irrigation. The results show that in loess landslides triggered by heap loading and unloading, vertical joints and cracks easily evolve into a fracture belt. Under the action of shear stresses, shear creep zones expand from the toe to the internal of a slope gradually and develop into shear zones that penetrate the slope, which leads to the overall deformation and failure of slopes. Physical model tests reveal that the loess landslides triggered by heap loading have a typical feature of two sliding zones in shallow and deep layers. The loess landslides triggered by irrigation mainly develop in the loess tableland edge. The long-term irrigation will uplift the groundwater and cause the formation of a saturated zone in the slope body. The creep shear failure then occurs to the slope under the gravity load, resulting in the start of a landslide. In addition, the large-scale fast loading process will cause the liquefaction of the shallow loess in the front section of the slope body, and eventually triggers long-range loess mud flow landslides.