Slope Stability Evaluation And Reinforcement Design On E22 Section Of Haizhou Strip Coal Mine

The stability problems of slope play a role in many realms of engineering such as mining engineering, hydraulic engineering and construction engineering. There are 12 general types and 48 specific kinds of geologic hazards in our country.Coast, landslip and debris flow are the most serious geologic hazards, and they result in great damage every year because that type of hazard belongs to hazard of moving rock and soil of slope.As far as can be determined, mechanics method and number analysis method are still the foundations which resolve the problem of geotechnical engineering. Computers have improved measurably in the past few decades, creating the proper condition and driving force for the development of the stability analysis of slope.Western countries began to study the coast control in the mid-19th century, but there is a lack of understanding of the quality and the law of motion of the coast at the earlier period. After World War II, along with development of economy and exploitation of national territory, artificial means of coast control seriously begin. The coast control improved greatly in the past five decades.The slope of Haizhou Strip Coal Mine is an outsize slope,with its length exceeding 1500 meters, and its height exceeding 300 meters. This slope has the characteristics of the slope of sedimentary rock, and its incline is close to the incline of its rock stratum. There are 8 weak intercalated layers in the rock mass of the slope.Various coastes have already slipped totle up 59 times at the non-working slope of Haizhou Strip Coal Mine.We can know that the coast of the non-working slope of Haizhou Strip Coal Mine slip down the weak intercalated layers in the rock mass of the slope, and according to the engineering geologic condition, the hydrogeological condition and the reconnaissance result about the coastes that have already taken place of the non-working slope. The first cause of coast is that the shear strength of weak intercalated layers is not big enough, and other causes are that mining engineering cuts off weak intercalated layers, ground water effect on rock , and blasting concussion act on the slope.Because the failure mode of the non-working slope of Haizhou Strip Coal Mine is due to the weak intercalated layers, the proper methods that can solve this coast problem are the method of Sarma and Morgenstern-Price. This paper actualized those two methods through GEO-SLOPE software. Acquiescent methods such as the method of Ordinary, Bishop, Janbu and Spencer were only the referenced methods. For the sake of educing more accurate result, This paper actualized the method of Excess Thrust and Sarma though the software that compiled by professor Chen jian ping of JI LIN University.This paper analyzed and evaluated the outsize rocky slope in two ways: one by analyzing stability of the slope by the method of limit equilibrium using the software of GEO-SLOPE and compiled by professor Chen jian ping of JI LIN University,The other is numerical simulation thought the process of FLAC-2D.From what has been researched above, we may safely draw the conclusion that the resultes of anaysis by the method of numerical simulation of FLAC and limit equilibrium are accordant, but the slip plane computed bythe method of numerical simulation of FLAC is more exactness, because this method simulates material behavior directly, looks for the most dangerous slip plane according to yield criterion and failure mechanism of material, and considers the effect of stress redistribution and the progressive development that destroy takes place during destruction.This paper has researched the control design of coast using the actual example of Haizhou Strip Coal Mine, and reinforced the slope by the method of using anchor cable and filling and pressing the slope's toe.The soundness of reinforced slope has yet to be determined. This paper tested the stability of reinforced slope by the method of limit equilibrium and numerical simulation of FLAC. The coefficient of stability of reinforced slope that computed by those two method is within the compass of design specification, so the control designe of coast that the paper devised and selected is safe and feasible.