Research On The Coal And Gas Outburst Controlled By The Distribution Regularities Of In-situ Stress In Baiping Minefield

In-situ stress is not only the main dynamic for coal and gas outburst but also the fundamental forces for causing deformation and damage in roadway and other underground geotechnical engineering. The risk that pressure rise, coal and gas outburst and rock burst is increasingly high with the increase of mining depth. Sliding structure and fault are development in Baiping minefield, and the stress distribution is extremely complex. The dangerousness of coal and gas outburst becomes increasingly pronounced and has been the major hazard to mine safety production with the increase of mining depth. Fully understanding the deep coal seam, sliding structure belt and in-situ stress distribution along the fault have certain directive meaning toward coal and gas outburst prediction and prevention.This paper systematically analyzed the coal and gas outburst controlled by the distribution regularities of in-situ stress in Baiping coalfield according to regional measured stress, mine exploration data and production data based on previous research.The research conducted numerical simulation by selecting representative EW and SN section with ANSYS finite element software. The research achievements are acquired as follows:Baiping coalfield mainly had experienced three periods of tectonic movement, and sliding structure and fault are developmental. The stress is main horizontal stress nearly east-westward in Baiping coalfield nowadays according to comprehensively analyzing regional measured data and focal mechanism data. The main influencing factors of stress distribution are different degree, lithology and topography and geomorphology.In this paper, the regression analysis was conducted for the stress changing with depth based on regional measured data, and the finite element model was established about EW and SN section according to geological data exposed by drilling and production. The results show that sliding structure and fault are the main factors influencing the uneven distribution of stress, and topographic relief has some influence on distribution of shallow stress.the stress distribution in the gliding structure has different characteristics, such as, the horizontal principal stress and the vertical principal stress are larger at the underlying rock of the cutting layer part, the stress concentrationat hinge zone is the most significant, the stress in the crushed zone is decreased and has tiny change in the bedding zone.In-situ stress played a control role in gas pressure, coal structure and coal seam permeability. The dynamic phenomenon of Bai Ping coal field is mainly controlled by the size of the ground stress, mine dynamic phenomena. are frequent occurrence at high stress area of sliding structure and fault structure.