Mechanism Of Destuction And Stability Evaluation Of Unstable Rock Mass At Zhongdong River's Both Sides

Based on the engineering project of unstable rock mass stability evaluation at Zhongdong River's both sides, the paper studies structure features of slope rock mass at Zhongdong River's both sides and comes up with the four forming patterns of unstable rock mass in research area, by collecting geological data and reconnaissance and related mechanics experiments. Through analyzing the distribution and development features of unstable rock mass in research area. By using stereographic method and Rocfall numerical analysis, the paper analyzes unstable rock mass stability, gets the influence scope and degree of perilous rock fall and accordingly puts forward responsive prevention and cure measures. The research results can provide engineering reference and construction theories for this project in the future. The main research results are as follows:(1) Structure features and forming mechanism of unstable rock mass in research area;Through field geological measurements and structure features analysis of side-slope rock mass in research area, there are three main destruction forms of side slope deformation: toppling destruction form, ripping destruction form and slipping destruction form. The forming mechanism of unstable rock mass mainly includes toppling rock mass, fitting-slope rock mass, hanging rock mass and isolating rock mass.(2) The distribution features of unstable rock mass in research area.Based on distribution features analysis of unstable rock mass of Zhongdong River's both sides, which is from field surveys and forming patterns of unstable rock mass in research area, the unstable rock mass of Zhengzhou An mainly distributes in anti-trend bed rock of side-slope ridge south and gradually-toppling slope of salting-in angular pebbles' accumulation body, which is under sharp cliff of side slope at 530 to 650 meters high. It is in stripe shape and south-north trend. The unstable rock mass of Wanzhou An mainly distributes in the top sharp cliff at 900 to 650 meters high, in stripe shape, in the mid-sharp cliff of side slope at 680 to 800 meters high, in strip shape from southwest to northeast, and accumulation-body cliff of the bottom of slope body at 350 to 450 meters high, in cambered surface and near the river.(3) Stability analysis of unstable side-slope rock mass.Taking the development of advantage structure surface and Rocfall distribution features into consideration, the possible movement region, formed by advantage structure surface of bed rock and road trend, is in a relatively-stable state at present. But we should pay attention to prevention and cure measures under airslaking and raining condition. By Rocfall numerical value analysis software, we can know, with the condition changing, unstable Rocfall will drop to river valley at the bottom of the slope. And its simulating maximum energy is up to 2000KJ when falling into river valley. The influence scope of Zhongdong River's both sides Rocfall is wide and its influence time is long. Per unstable rock mass features, the paper puts forward some related prevention and cure advice like initiative net, guniting or avoiding.