Stability Analysis And Prevention Measures Of Laoying Rock Bodies After Earthquake

The collapse site of dangerous rock of Laoying rock bodies is located on the right bank of Dadu River in Jinshui Village,Guzan Town,Kangding City,Ganzi Prefecture,Sichuan Province.The fracture development and integrity are poor.The study area is located in an earthquake prone area with an earthquake intensity of 9degrees.Earthquakes cause severe deformation of rock mass,resulting in instability and collapse or in a state of motion without collapse.In addition,rainfall,slope cutting and road construction at the foot of slope promote the generation and development of new and old cracks in rock mass.According to the investigation,many times the Laoying rock bodies collapsed,seriously affecting the life and safety of the residents at the foot of the slope and the safety of vehicles on the foot of the provincial highway S211.Therefore,studying the formation mechanism of dangerous rock collapse,the stability status of dangerous rock mass and prevention measures in this area,which has practical significance and guiding significance for post disaster governance and residential area location in the area.Firstly,through the collection of geological data,field exploration and indoor geotechnical experiments,the geological background of the study area is grasped,and the dangerous rock in the study area is divided into three dangerous rock zones,one independent dangerous rock mass and three falling accumulations.The formation and development process and failure mode of dangerous rock collapse are studied and analyzed.The factors of affecting the formation and development of dangerous rock are summarized.Earthquake and heavy rainfall are the main factors to promote the development of dangerous rock and the occurrence of instability and collapse in the study area.Secondly,on the basis of studying and analyzing the development and failure mode of dangerous rock,the stereographic projection method is used to qualitatively analyze three dangerous rock zones,and the stability status of dangerous rock zones is determined;By combining quantitative calculation and numerical simulation software FLAC3 D with empirical formula method,the stability status of independent dangerous rock mass and falling accumulations and the stability under special conditions are simulated and analyzed.Finally,based on the research results of the stability of dangerous rock,considering the steep slope of Laoying rock bodies,dangerous rock is mainly located in the middle and upper part of the slope,it is suggested to clean up the dangerous rock and set up passive protection net for the treatment of the collapse of Laoying rock bodies;By choosing the representative large dangerous stones on the slope and applying the theory of kinematics and energy conversion theory to analyze the movement characteristics of the dangerous stones and determine the height and energy level of the passive protective net.