Evolution Characteristics And Application Of Permeability Of Mining Coal Body

The gas problem of coal face is the key problem that restricts the safe production and efficient mining of coal mine,especially for the high gas coal seam.In this paper,the 3#coal seam of a coal mine is taken as the research object,and the method of experimental research,theoretical analysis and numerical simulation is used to study the evolution characteristics of coal permeability in the process of mining,and it is used in the field engineering practice.By collecting coal samples on site,using gas-solid coupling triaxial seepage test platform and rock mechanics test system?GCTS?to carry out pre peak loading and unloading experiments on coal samples,to study the evolution law of internal fractures of coal samples under different loading and unloading rates;further,the post peak loading and unloading experiments on coal samples are carried out,to explore the permeability change characteristics of coal samples,and to observe the pre peak loading and unloading seepage test process The change of micro pore size and pore throat of damaged coal.Based on the principle of damage mechanics and the damage accumulation characteristics of coal body,the permeability model of damaged coal body with damage factor7)₉)??is established,and the quantitative relationship between permeability and stress of damaged coal body is discussed.Taking the field engineering practice as the object,the non inline function of the advance bearing pressure of the working face is established,which is imported into the COMSOL numerical simulation software,and the gas emission law of the working face is studied in combination with the permeability model of the damaged coal body.The relationship between the gas pressure and the gas emission in the coal seam of the working face with time is explored,so as to guide the safe and efficient opening of the working face.It can be used for reference.There are 51 figures,5 tables and 58 references in this paper.