Study On Stability Of Slope During Turning Open Pit Into Underground Mining In High-steep Area

The balance of original stress is destroyed in the course of open-pit into under mining, which bring displacement of slope and surface in main area. Commonly the movement is divided into global and local forms. Horizontal movement and subsidence in nearby surface is represented in global change, while collapse and fall-roll of slope rock is repressed in local. In order to guarantee ordinary operation, maintained operating personnel and equipments and protect mineral resource and surface environment, the analysis and expectation of slope stability are imperative as well as reasonable implementation of safety protection based on the analysis results.Taking the open-pit slope at Hundong Lead-Zinc Mine as object, the stability of slope during turning open-pit into under mining is studied. Firstly, collecting and summarizing observation data of slope distortion in mine to build distortion mathematics model. Genetic programming is used to analyze and predict the slope stability, and validating the prediction accuracy of this technique contrasting observation data. Secondly analyzing the collapse and fixing on the area that eventspossibly occur, ensuring that the loose petrofabric in north side of west slope and the west strict of F₁₅ fault. The principle of probability statistics is used to simulate the course of rockfall at typical section. The result shows that the influence scope of rockfall is 60-80m and jumping height and kinetic energy variations is relatively small. Protection of rockfall is provided according to the statistical results. Finally protective measures are proposed by the results of studies, meanwhile analyzing the reliability and rationality of defenses by means of physical process.The computer intelligent analyses, expectation and simulation are used in study of slope stability as well as modern analysis method, which embodies some trends on treatment of geotechnical engineering.