The Simulation And Study Of The First Weightingon The Working Face With Large Mining

During the National "Eleventh Five-Year" period , China want to form 6 to 8 hundred million ton and 8 to 10 5 000-ton large-scale coal enterprises, production accounting for more than 50%. Shanxi coal "mergers and acquisitions" is in response to this goal generated. It is said that the integration of coal resources is the development of large coal production bases and resources, a prerequisite for protection. The large coal companies are busy on the acquisition, merger of small mines to conduct technological transformation and expansion. How to make a limited capital investment to produce the greatest economic benefit? How can companies in the short term capacity be raised to a higher level?Many mines in Shanxi coal seam have No. 3 and No. 15 coal seam, such as Jincheng, Changzhi, Datong, Yangquan, Linfen and Yuncheng. The average thickness of coal in the 3.0 ~ 6.0m, the overall stability of coal development, roof and floor conditions were better, in this coal seam conditions, a full height is the preferred method of mining.With our country's production improving, large mechanized equipments will be gradually integrated into mine. The overall height mining at a time will be a developing trend in the future for the coal seam of more than 4m thick. However, the overall height mining at a time has its restrictions such as, the size of wellhead, roadway cross-section dimensions, geological structural development on the face, the condition of top and bottom roof, and so on. When many factors meet the circumstances, the top roof condition seems more important. The top roof condition directly determines the feasibility of the overall height mining at one time, aso is an important reference indicator for type selection of hydraulic support. Many studies have demonstrated that with the working face advanced, hydraulic supports will get a lot of pressure from top roof. The increasing resistance of hydraulic supports is greater, especially in the process of periodic roof pressure and first roof pressure. If the unsuitable support type is selected, it will cause the support to fall down or break, and the top roof fall during periodic roof pressure and first roof pressure, even seriously result the roof collapse, or hurricanes, which triggered mine geological disaster.This paper carried on field coring and laboratory mechanics tests in view of the 3# coal bed and top roof in Wang village coal mine, Chang zhi, analyzed rock mass structure and mechanics characteristic of coal bed and roof. Using the high stope roof control theory, through the FLAC3D similar simulation, it studied the high stope roof structural feature in Wang village coal mine, Changzhi, and provided some bases for the feasibility of the large cutting height mining in this region.