摘要
研究胜利东二号露天煤矿南帮红层边坡系列滑坡的下滑机制。采用地质勘探的方法,确定南帮边坡的断层分布和地层特性;通过现场踏勘和4次无人机航拍图的对比,从现象上分析了滑坡各个区域的变形破坏特点;利用GPS监测设备所获得的数据,定量分析2次巨型滑坡的变形特征;结合钻孔信息,分析得到变形区滑动面的位置。在对南帮边坡地层结构和水的作用的概化基础上,利用物理模型试验对其破坏演化机制进行定性探索。研究表明,南帮边坡坡脚F68断层的隔水特性,砂泥岩互层的变形差异,以及大量分布的、抗剪强度很低的弱层是造成系列滑坡的主要地质因素,降雨强度的增长加剧了边坡的变形。砂岩、泥岩分属于硬岩和软岩,且泥岩遇水易软化;砂泥岩层的差异变形造成砂岩陡倾节理张开扩大,地表水较易入渗;同时由于地下水在F68断层处无法消散,从而造成坡脚的溃烂破坏和坡面裂缝带的形成。在暴雨条件下,雨水下渗软化弱层,在弱层上存在较高渗透水压力,坡体后缘裂缝带内形成静水压力,这些因素导致边坡发生多级"平推式"滑坡。
Sliding mechanisms have been studied for the series of the landslides of the southern red bed slope in the No.2 opencast coal mine in eastern Shengli coal field. The geological exploration is used to determine the distribution of the faults and the properties of the strata. By field survey and comparison of the four images photographed by an unmanned aerial vehicle,the deformation and failure characteristics of every landslide area are analyzed phenomenally. Using the monitoring data of the GPS,the deformation characteristics of the two large landslides are analyzed quantitatively. Combined with boreholes＇ information,the slip face of the deforming area is obtained. Based on the generalization of the stratum structure and the effect of water,a physical model experiment is made to qualitatively explore the failure evolution mechanisms of the southern red bed landslide. The research shows that,the watertight property of the F68 fault,the different deformation between the sandstone layers and mudstone layers,and the distribution of lots of weak layers with low shear strength in the southern slope are the primary geological factors resulting in the series of the landslides,the increase of the rainfall intensity aggravates the deformation of the southern slope. In fact,Sandstone and mudstone belong to hard rock and soft rock respectively,and the mudstone softens easily when encountering water;because of the different deformation of sandstone and mudstone,the steep joints in the sandstone become open and then the surface water infiltrates easier;besides,the groundwater cannot dissipate in the F68 fault. All of the above reasons cause the ulceration at the toe of the slope and the formation of the fracture zones on the surface of the slope. Under the condition of the rainstorm,plenty of rainwater infiltrates and softens the weak layers,the higher seepage water pressureexists in the weak layers and the hydrostatic pressure forms in the fracture zones,consequently leading to the multistage ＂horizontal-pushing-type＂landslides.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2016年第A02期4063-4072,共10页
Chinese Journal of Rock Mechanics and Engineering
基金
国家重点基础研究发展计划(973)项目(2015CB250903)
中国科学院战略性先导科技专项(B类XDB10030303)~~
关键词
边坡工程
露天煤矿
模型试验
演化机制
slope engineering
opencast coal mine
model experiment
evolution mechanisms
