黄土滑坡诱发因素及其形成机理研究

近年来,黄土滑坡灾害发生频率呈现增加的趋势,研究黄土滑坡诱发因素及其形成机理是有效减缓黄土滑坡灾害风险的基础。据西北黄土高原地质灾害详细调查,黄土滑坡的诱发因素有自然和人为2类。自然因素包括地震、河流及沟谷侵蚀、降雨及冻融等; 人为因素有堆载与开挖、农业灌溉、修建水库等。研究表明,降水和人类工程活动是最积极的诱发因素。地震加速度引起的抛射作用和粉尘化效应以及振动液化效应是地震诱发黄土滑坡的主要原因。河流的侧向和下切侵蚀作用在河流的不同发育期诱发机理有所不同,导致斜坡变形破坏模式也有所区别。冻融作用诱发黄土滑坡的机理类型分为冻结滞水效应型和融化强度降低型等。降水作用诱发黄土滑坡的机理按触发滑坡的降水特征分为暴雨型和淋雨型,按地下水的作用方式分为优势通道-局部地下水型、地下水位上升型和增重型等。诱发黄土滑坡的人类工程活动分为斩坡型、灌溉型、水库型、堆载型等。

TRIGGERING FACTORS AND FORMING MECHANISM OF LOESS LANDSLIDES

In recent years,the frequency of loess landslide occurrences has the trend of increasing.It is a basis of reducing the landslide hazard risk to investigate the triggering factors and forming mechanism of loess landslides.Field investigation for geological hazards on the Loess Plateau suggests that the induced factors of the loess landslides mainly include earthquakes,precipitations,frozen-thawing,river erosion and human engineering activities.Among them,precipitations and human activities are the most activ...