Study Of Overburden Failure In Shallow Seam Water-rock Coupling Effect

China Shenfu-Dongsheng coalfield is located in Western Inner Mongolia, northern Shanxi and Northern Shanxi which is the largest piece of coal at present development with simple mining and geological conditions and prominent characteristics of fragile ecological environment. The main aquifer in the area of Quaternary Sara Wusu group, it is unconform in the Jurassic bedrock aquifer, the whole region is the survival of the water system, that the water resources mainly by surface precipitation are very valuable. It is understood, coal development does not destroy the local ecological environment as the price, has the important practical significance and long-term development of shallow coal fields in western the strategic meaning of the mechanism of water resources and water resources protection.This article through the theoretical analysis and computer numerical simulation methods of the western ecological fragile mining of shallow seam mining under the coupling effect of water rock strata damage rule system research. The specific contents and research results of this paper is as follows:(1)According to the key strata theory in ground control, at the same time, combined with the prominent characteristics of the structure of the shallow buried coal seam, the theoretical analysis of the overburden layer plays a key role in the structure stability of the decision with the stability of the overlying soil layer insulation, so the stability of the analysis of the key stratum structure for the roof aquifer protection has the very big effect. The key stratum structure under the action of overburden load will produce a bend, bend when the key stratum structure is greater than its maximum deflection limit deflection, the key stratum structure is about to break. At the same time, using mathematical and mechanical analysis method of shallow buried coal seam isolate water of soil layer to keep the water criterion, and provide theoretical basis for the prevention and control of coal mine roof water inrush.(2)Based on computer numerical simulation method, and connecting with the actual situation of mine, study on2301face, due to the2301face in field tests a produced coal thickness of3.5m, immediate roof for2.0m thin mudstone, immediate roof fall behind not full of mined-out area, so the scope of the main roof breakage range extends from higher levels. FLAC program for different length of working face under the coupling effect of water rock overburden damage has carried on the contrast analysis, obtained in the working face length under the influence of the stress, displacement and plastic zone distribution, and above the mining of coal seam, layout of measuring line of overburden as the law of mining damage under the influence of monitoring, in the process of working face advancing, the overburden stress and displacement of the cycle of changes have taken place, the development regularities of lead water fracture zones were analyzed, and also for the shallow buried coal seam under the coupling effect of water rock strata damage rule to do the monitoring and summary of the system. Also application experience formula method, it is concluded that the coupling between seepage and stress analysis of the thin bedrock shallow buried coal seam under the action of fluid-structure interaction, the change law of overburden rock permeability coefficient.