Study On Surrounding Rock Control And Support Type Selection Of Fully Mechanized Caving Mining Face With Residual Coal

Coal is a non-renewable resource.Therefore,it is imperative to back up high-quality resources in the residual coal recovery zone.The rational selection of supports for fully mechanized top coal caving mining face in residual coal can effectively control the deformation of surrounding rock and realize high-yield and high-efficiency production.At present,the domestic and foreign scholars' research on the residual mining mainly focuses on the stress distribution and mine pressure Characteristics of the surrounding mining face.However,there are few researches on the selection of the supports and they cannot effectively guide the practice.This paper takes the fully mechanized top-coal caving face in Guanlingshan Coal Mine as a geological prototype.Through the theoretical analysis and numerical simulation research methods,the stress distribution and transfer regularity of surrounding rock,the deformation of the surrounding rock and the work resistance of the support in the fully mechanized top coal caving mining face are Studied.The main contents and conclusions are:(1)The analysis of the fracture process of the basic rock block of the residual and integrated coal mining face shows that: the width of the empty roadway and the compression deformation of the coal pillar are the main factors affecting the basic roof fracture,and the coal pillar compression deformation is the main factors that cause the migration of surrounding rock and the stress evolution of the stope.The limit conditions for the occurrence of the super-large rock fracture are: the basic top limit breaking length is equal to the sum of the empty roadway width,the width of the coal pillar,and the length of the suspended roof at the back of the working face coal wall,and the length of the suspended ceiling at the rear of the working face coal wall reaches its periodic weighting length.(2)Analyze the evolution law of roof support pressure migration of the residual coal mining face,establish the interaction mechanics model of Support and surrounding rock when working face passes the coal pillar and empty roadway,and obtain the corresponding calculation formula of the work resistance of the support.(3)The method of numerical simulation was used to study the surrounding rock deformation and support work resistance of the residual mining face,and the calculation formula for the support working resistance of the fully mechanized top face was obtained.The width of the empty roadway,the width of the coal pillar,the thickness of the coal seam,the depth of the coal seam and the height of coal cutting are the main factors affecting the work resistance of the support.The order of the influence of each factor on the work resistance of the support is: empty lane width> coal pillar width> coal height> coal seam depth> coal seam thickness.(4)The breakage length of the leading edge of the basic roof increases with the increase of the width of the empty roadway;the stability of the end face of the support top beam decreases as the height of the cutting coal increases;The work resistance of the support is positively correlated with the width of the empty roadway and the depth of the coal seam.The height of cut coal and the width of the pillar is negatively correlated;when the thickness of coal seam is less than 8m,the working resistance of support is positively correlated with the thickness of coal seam.When the thickness of coal seam is greater than 8m,the work resistance of support is negatively correlated with the thickness of coal seam.(5)Comparing the calculation results of various formulae,select the type of support for the Guanlingshan coal industry,and analyze the adaptability of the selected ZFS5600-16/32 hydraulic support and the law of rock pressure appearance of the surrounding rock.The analysis shows that the selected support can meet the need of safe production.