开挖型黄土滑坡发育特征统计分析

Statistical analysis of excavation model of the loess landslide developmental characteristics

近年来,黄土高原地区由于工程开挖活动的不断加剧,引起工程性的灾难性黄土滑坡不断增加,而对开挖引起黄土滑坡的发育规律与特征认识不清。为此,在野外调研的基础上,对典型工程开挖所引起的黄土滑坡,分别从滑坡的分布特征、后壁特征、坡高对滑坡产生的影响以及滑坡后缘裂缝特征进行数学统计分析,结果表明:(1)在分布上分别具有:地貌的选择性、地层的选择性、条带状分布特征;(2)在开挖方式上表现为快速开挖和蠕动开挖;(3)滑坡后壁陡坎高度受上层马兰黄土厚度控制,其后缘裂缝的发育呈"雁羽式"和"双耳"状特征,对后缘演化机制进行了探讨。

In recent years,with the engineering excavation activities increase in loess plateau,disastrous loess landslide caused by engineering works also increase.It also resulted in misunderstanding of regularities and characteristics of the development of loess landslide.In order to solve this problem,on the basis of field investigation,the paper conducted statistical analysis on loess landslide caused by typical engineering works from aspects of distribution characteristics,backwall characteristics,effect of slope height on landslide,and characteristics of fissures of landslide rear edge.Results indicated that：（1）the distribution was characterized by selectivity of landform,selectivity of formation and banding;（2）the methods of excavation included fast excavation and creep excavation;（3）the scarp height of landslide backwall was controlled by thickness of upper Malan loess,and the fissures in the rear edge occurred as＂goose feather＂or＂binaural＂in form.The paper also discussed the evolution mechanism of rear edge.