Stability Analysis And Countermeasures Of Mining End Slope In Dafeng Open Pit Coal Mine

Slope failure is the main disasters of open mining in large opencast coal mine of Shenhua Group as the peak the main coal producing areas.After underground mining turn to open pit mining,with the increase of mining depth,local landslide accident frequently.Although it had no great loss of personnel property,caused a certain influence for the production.Due to the high overall slope of the design and the development of the slope joints,the safety of the slope will restrict the mining and the development of the enterprises.Therefore,the stability of the end slope is studied by the background of Dafeng opencast mine.The main contents are as follows:(1)By engineering geological analysis,the geological structure and slope bedding structure are grasped.According to the distribution characteristics of bedding,the potential failure mode of the slope and slope failure can be divided into the non working wall as an example of the landslide and landslide along the arc to end as an example the.(2)The theoretical analysis method is used to calculate the theoretical safety factor of the two types of slopes,to change the parameters of the related structures,to calculate the parameters of the different structural parameters and the change characteristics of the safety factor.The slope angle and the step height have the greatest influence on the stability of the slope,and the step height andthe slope angle of the slope are finally ended.The critical value is 15 m and 70 degrees.(3)The results of theoretical analysis were verified by numerical simulation.The stress variation characteristics of potential slip surface were analyzed by FLAC3 D directly through stress cloud diagram.At the same time,the optimum final slope structure parameters are determined by the orthogonal test analysis.In a word,the optimal structural parameters of no-working wall are as follows:the step height is 10 m,the angle of the step slope is 70°,the width of the flat plate is 5m.The optimal structure parameters of end slope are as follows: the step height is 15 m,the step slope angle is 70°,the width of step flat plate is 3m.(4)Through a lot of examples of slope,summarizes the slope protection measures,and according to the actual situation of the large peak of open-pit mine and puts forward three protective measures: 1)slope parameter optimization;2)study on blasting technology of slope control;3)other measures,such as drainage engineering,anchoring technology,slope monitoring technology etc..Through the actual engineering geological analysis,a theoretical model is proposed according to the different features of rock slope,then Flac3 D numerical analysis method was used to calculate safety factor,finally puts forward corresponding protective measures,combined theory,simulation and field practice,the research results of the end slope of Dafeng open pit coal mine have high practical value.