Study On Key Parameters And Control Technology Application Of Gob-side Entry Retaining With Roof Cutting

Gob-side Entry Retaining has obvious advantages in alleviating the connection tension of working face,reducing the loss of coal resources,reducing the length of roadway excavation and eliminating the gas in the upper corner of roadway.It has been applied to varying degrees in coal mines.Through various roof cutting technologies,the gob and the overlying strata of the gob-side entry retaining with roof cutting are separated,the stress condition of roadway is improved and the surrounding rock structure is maintained stable.In this thesis,taking the Donglian Roadway of 25 Coal Pillar in a mine as the research object,the control mechanism and key technical parameters of surrounding rock stability of gob-side entry retaining with roof cutting are comprehensively studied by means of field measurement,theoretical analysis,numerical simulation and industrial test.The main conclusions are as follows:(1)The characteristics of ground pressure without roof cutting in Donglian Roadway are expounded.The borehole peeping and roadway deformation monitoring are carried out,and the characteristics and causes of roadway deformation are analyzed.(2)The mechanism of roof cutting by presplitting blasting is studied.By cutting the roof to reduce the suspended roof area,a "short arm beam" structure is formed to reduce the influence range of surrounding rock stress concentration.After the cutting height reaches the basic top,the leading support stress and lateral support pressure of the working face are reduced,and the surrounding rock deformation is small.(3)The model of roof cutting and roadway formation along the goaf is established,the key technical parameters of roof cutting and roadway retention in Donglian Roadway of The 25 Coal Pillar are determined,including roof cutting height,and roof cutting angle,the stress distribution of roof cutting and pressure relief surrounding rock is revealed,and the technical scheme of roof cutting and roadway formation in the East reconstruction of The 25 Coal Pillar is put forward(4)The research results were tested in the field.The practice shows that the roadway can meet the production requirements of the working face and create good technical and economic benefits after adopting the roof cutting retaining roadway and the corresponding roadway surrounding rock control scheme.This thesis has 61 figures,2 tables and 81 references...