The influence of underground mining direction on cordinated open-pit with underground mining slope stability and optimization

In order to get the optimal arrangement of space position between underground mining working face and open-pit mine slope in coordinated open-pit with underground mines,three schemes was designed to study the situation of underground mining disturbed open-pit coal mine slope under different layout direction of underground mining face under the background of coordinated open-pit with underground mining engineering practice in Pingshuo mining area. The results show that the adverse effect on the stability of open-pit coal mine slope which caused by underground mining is the lowest when the direction of underground mining face and dip direction of open-pit coal mine slope is parallel. Through the optimization analysis of underground mining direction when the underground mining face layout according to the above way,it finds that underground mining direction is along the inverse slope direction,the disturbance of open-pit coal mine slope produced by underground mining is more obvious compared with along slope mining. In coordinated open-pit with underground mining practice,the direction of underground mining face should layouted parallel with dip direction of open-pit coal mine slope,and the underground mining direction should choose along slope direction,so that the adverse effect on slope stability caused by underground mining will be reduced and recovery rate of coal resources will be improved.