Investigation On Repeated Mining Technology Of Failurezone In Xinliu Coal Mine

In the process of coal resources integration and reorganization, the management of failure zonein the small coal mine is particularly important. Taking Fenxi mining area as an example, the coalresources stoping rate of small coal mine is only10%~25%since the outdated mining technologysuch as room and pillar mining method was employed. According to incomplete statistics, the totalarea of failure zones formed by the outdated mining technology in the small coal mines amount tonearly one hundred square kilometers in Xinliu, Xinyu and Xinyang coal mines. Therefore, areasonable extraction technology of the longwall panel should be employed to recovery these coalresources. Based on the geological conditions of0902longwall panel in Xinliu coal mine, thisstudy presents an integrated approach for field tests and numerical investigations to assess theeffectiveness of the extraction technology. Protem EM-47transient electromagnetic instrumentwas employed to detect and locate the place of abandoned tunnel of goaf. According to the resultsof transient electromagnetic instrument, A3D-geological model was established by FLAC3D (FastLagrangian Analysis of Continua in3Dimensions) to understand abutment pressure distribution ofthe longwall panel when the mining face is passing through the abandoned tunnel of goaf.Meanwhile, the reasonable pattern of slope adjustment mining is analyzed as well. The results ofthe field tests and the numerical modeling show that the mining face closed to the haulageroadway should be advanced20m than that closed to the material roadway. Because of the slopeadjustment mining, stress concentration does not occur in all of the pillars at the same time. Inaddition, the abandoned roadway is not damaged in the process of mining while the failure ofmain roof does not occur. Therefore, the reserved coal resources can be recovered smoothly.