Study On The Mining Technology Of Protective Pillar For Industry Square Structures In No.7 Coalmine Of Pingdingshan Coal Group

With the exploitation of the coal,the problems of mining under “three body” and ecological environment protections are more and more serious in China’s coalmines.In order to exploit these pillars under structures and lengthen the mine service life,as well as to protect the ground buildings,it’s necessary to study the mining technology.Based on the mining under industry square in No.7 Coalmine of Pingdingshan Coal Group,the small strip panel mining technology is studied through the scheme contrast and selection,theoretical calculation,the probability integral method analysis and numerical simulation etc..This method is one of the mining technologies under structures to change the mining and pillar width combined with the strip mining theory and the actual restriction.By comparing the common mining ways in domestic and overseas,the small strip panel mining scheme is determined and studied in terms of the geological mining conditions.At the same time,the prediction parameters of utmost non-full extraction condition are got,the influence of earth surface movement and deformation on the structure is analyzed.The results show that the surface building damage level is within the range of grade I influence when small strip panel mining method is adopt.The subsidence basin movement and deformation laws of repeated mining as well as displacement of surrounding rock and shafts are also analyzed,and the results show that the method is good for controlling the overlying strata and liberating the coal pillars.At last,it establishes surface subsidence surveying station and building movement surveying station and puts forward practical monitoring design,which provides technology support for mining optimization design and surface subsidence control.The research results show that: it is applicable to adopt this method mining under structures,and this method protects ground building by the way of decreasing mining destruction,besides,it extends the mine service life and improves the coal recovery rate.