Study On Longwall Mining Pressure And Control Beneath The Area Mined With Longwall-Pillar Method In Ultra-Close Multiple-Seams

Longwall mining beneath the area mined with longwall-pillar mining method in ultra-close multiple-seams is the distance of the two coal seams is very short, superstratum coal seam use longwall-pillar mining method, underlayer coal seam use longwall mining. As for very short distance coal seams, along with the distance of coal seam reduce, the interrelationship of the two coal seam mining is increased. When the distance of the two coal seams is very short, underlayer coal seam will suffer different degree damnification which is from superstatum coal seam mining, and so as to the floor structure occur change transformation. The presentation of the mine pressure in working face, the control relation of the support and surrounding rock mass, the lay characteristic and Support fashion of the mining roadway, the stoping technology and security technique etc. all of them have particularity. Especially for this condition, the ultra-close multiple-seams, superstratum coal seam use longwall-pillar mining method, underlayer coal seam use longwall mining method, the floor of the working face and roadway will engender severity distortion, so much as breakage, the floor fall and leak easily, all of this phenomenas occurred by the superstatum coal seam mining. When the working face and the roadway communicate the longwall-pillar gob area, the working face will come into being air leak, and influence mine security production badly.As a result of this case in practice less appearance, at present, this aspect system theoretics is also devoid. Because of the seam 8 in Wangfeng coal mine use longwall-pillar mining method, now the mining of this coal seam is about to accomplish. However, the seam 9 which is situated the seam 8, the average distance of the two coal seams just only 0.75m, the quality of the seam 9 which thickness is 3.33m is the best in Wangfeng coal mine, in order to improve the rate of cutting coal, prolong service time of the coal mine, Longwall mining of the seam 9 beneath the gob area of the seam 8 mined with longwall-pillar mining method in ultra-close multiple-seams is put forward in Wangfeng coal mine.Aiming at the mining condition of seam 8 in Wangfeng coal mine, by locale investigate and research, physical mechanics parameter experimentation of the surrounding rock mass, academic analysis, Ansys software numerical simulation calculation, the mine pressure and it's the presentation in roof of the seam 8, the ascertainment of bearing strength and stability pillar, in concentration load condition, the stress transmission orderliness of floor, the mine pressure and it's the presentation in roof of the seam 8, strut resistance setting and pressure of working face supports confirm, the mine pressure control of the roadway and so on, all of them are researched, for the sake of solve similar the question of Longwall mining method which beneath the gob area mined with longwall-pillar mining method provide reference gist and inaugurate new approach.Consequently, as for the mine pressure and control in very short distance coal seams, not only enrich the theory and practice of the very short distance coal seams, but also have important realistic meanings and apply value to expand main work and increase the extraction ratio for little coal storage Wangfeng coal mine.