Research On Coal Gas Permeability Evolution Law In Advanced Abutment Pressure Zone Of The Stope

Shoushan mine adopts bedding borehole in working face gas control,bedding boreholes which are located in 20 m advancing working face be dismantled timely during mining process, inducing drilling gas concentration keeps at a high standdrd. Therefore this paper researches on coal gas permeability evolution law in advanced abutment pressure zone of the stope,which will provide referance on what time to dismantle bedding boreholes.This paper takes Shoushan mine 12050 working face as the research object. Obtaining the size of advanced abutment pressure zone and the stress peak position through observing 12050 haulage entry deformation. Getting preliminary coal gas permeability changing trend by observing drilling gas concentration and gas absolute amount in bedding borehole. Having a research on bedding borehole deformation feature and advance vertical stress with ultimate stress equlibrium theory and FLAC3 D numerical simulation,getting advance vertical stress distribution law of 12050 working face. Using COMSOL-Multiphysics numerical simulation to construct model of extracting gas with bedding borehole,having a research on coal gas permeability distribution in advanced abutment pressure zone of the stope,obtaining coal gas permeability evolution law in advanced abutment pressure zone of the stope. In the view of coal gas permeability, 11 m in the front of working face is better to dril gas, as a result, optimizing the demolition of bedding borehole.