Study On The Control Technology Of Surrounding Rock In Roadway Of Compoundroof With Coal In Jinxinda Colliery

Compound roof is rather common in mining and extraction process. Supporting system in compound roof is a difficult point in mines’ supporting. Compound roof with coal refers to that coal is beneath the roof. Compared with ordinary compound roof, the coal and rock mechanical properties in compound roof with coal are greater, and roadways are more easily destoried.Aiming to #1101 transportation roadway in JIN Xinda colliery, according to theoretical analysis, computer investigation and field practice, this paper reveals deformation characteristics of instability and impact factors in compound roof with coal, and puts forward reasonable supporting methods. Perfect supporting effects are achieved with several conclusions below.(1) This paper points out deformation characteristics of instability and impact factors in compound roof with coal including serious roof of roadway deformation and destruction, large amount of separation layer, sudden destroy of roadway is obvious, displacement of roadway floor is greater.(2) According to building differential equation of deflection line of roof, this paper analyzes variation of layers and reaches a conclusion that different deflections of layers in roof result in separation layers in compound roof.(3) This paper analyzes different factors in roadway stability including height of roadway, width of roadway, cover depth of roadway and son on. According to numerical simulation, surface displacement of roadway, deep displacement of surrounding rock, distribution of stress and plastic zones are determined. Based on these, a more reasonable roadway section can be designed before extraction.(4) Based on deformation characteristics of instability and impact factors in compound roof with coal, this paper puts forward a surrounding rock control technology which is based on high strength and high pretensioned stress bolts. This paper researches mechanism of high pretensioned stress bolts and impact on surrounding rock stability. This paper deduces the relation between Lateral extrusion stress and bolts distances when one or several bolts works according to mechanical computation.(5)This paper determines supporting parameters in #1101 transportation roadways in JIN Xinda colliery and conduct a field test with a perfect surrounding rock control effect. At last Enormous social and economic benefits are achieved in this colliery.