Study On Characteristics Of Surrounding Rock Loose Circle Based On Yuxi Coal Mine

According to the field conditions of Yuxi coal mine,this paper uses the method of numerical simulation and field measurement to study the distribution and evolution law of the loose zone of the surrounding rock under the conditions of different buried depth and different sections.It can provide the basis for the selection of roadway support and reasonable hole sealing parameters.This paper mainly studies the following aspects:(1)The stress distribution of surrounding rock in loose zone,plastic zone and elastic zone is analyzed theoretically.This paper studies how the factors such as in-situ stress,cross-sectional area and rock mass strength affect the sealing depth.(2)By using the numerical simulation software of COMSOL multiphysics,the loose zone of surrounding rock of roadway with different section shapes(trapezoid,arch,rectangle)and different section areas(15m~2,20m~2,25m~2,30m~2)is simulated.The evolution rules of stress and strain of surrounding rock,loose zone of surrounding rock and displacement of roof and floor of roadway are obtained with the increase of section area and the change of section shape.(3)According to the actual situation of Yuxi coal mine,the distribution of surrounding rock loose circle in different roadways was tracked and investigated.The gas flow method is used to analyze the actual distribution of three zones in Yuxi coal mine.According to the results of theoretical calculation and numerical analysis,the sealing depth in the field is analyzed by comparing the field measurement data.In this paper,the stress distribution of the two sides of the roadway and the distribution of the loose circle around the roadway are analyzed.The evolution rules of stress distribution around the roadway,the size of loosening circle and the displacement of roadway roof and floor with the cross-section area and shape are obtained,and the results are verified by field test.