Study On The Reasonable Horizon And Stability Of Upper Coal Mining In Upper Coal Seam Under Upward Mining

Many areas in China are faced with the problem of resource depletion,in order to effectively recover the surplus resources,most of the mines are preferred on the cross(the)mountain mining form.This method helps to reduce the amount of excavation roadway especially floor roadway,so as to achieve a good effect of saving production cost.However,(under the mountain)in the unaffected cross mining,roadway maintenance in good condition,once under severe pressure effect in cross mining,roadway maintenance becomes very difficult.Therefore,how to control the cross mountain rock stability has become urgent need in the production process to solve the problem.As the engineering background of Haizi coal mine 83 mining area roadway of 736 working face down by mining disturbance,and the roadway in the lower 10 coal recovery after the above goaf surrounding rock,the harsh external environment.In this paper,through theoretical analysis,numerical calculation,similar tests and field measurements of a variety of ways to explore in the lower coal seam mining the above goaf,rational layout of regional downhill road;the influence degree of various factors on the cross mining roadway surrounding rock stability,at the same time according to different deformation failure dynamic pressure roadway put forward reasonable reinforcement measures,and field test.The main research results are as follows:(1)based on the numerical lower 10 coal stope surrounding rock mechanics and rock movement simulation,the goaf overburden height and pressure relief range.(2)the construction of supporting stress increment mechanics model of mining,analyzes the propagation law of the abutment and the lateral support pressure in the floor,and on the basis of Moore-Kulun model on the range of destroyed floor 7 coal face.From the analysis of the main factors influencing the scope of fractured rock mechanics and supporting of surrounding rock.And discusses the different stages of deformation and failure of cross mining roadway.(3)through numerical simulation,comparison and analysis of the stability of the surrounding rock of different tunneling position,estimate the reasonable position of roadway layout.By comparison of the numerical simulation analysis of 10 coal mining,influence the stability of the surrounding rock road lane 7 in the process of coal mining disturbance,the roadway is located in different locations,different positions the relationship between the surrounding rock and the surrounding roadway with different lithology of roadway surrounding rock deformation and stress distribution evolution characteristics.The results show that the distance of roadway and working face closer,surrounding rock lithology is worse,and the surrounding roadway distance closer,deformation and damage degree of surrounding rock is serious;10 coal mining before and after downhill Roadway Influenced by mining the overall evolution is basically the same,but the 10 coal mining stress concentration is smaller,and the deformation of surrounding rock is less.With the similar simulation test further demonstrated in the 7 coal mining roadway The effect of various factors on the surrounding rock of roadway(4)on the basis of theoretical analysis,numerical analysis and test of similar conclusions and combined with the actual situation,to ensure economic and reasonable supporting effect of the premise,put forward different reinforcement measures to roof grouting + hanging beam cable of roadway section.After the period of working across observation shows the reinforcement measures made a good effect on the control of roadway deformation.