Simulation of recovery of upper remnant coal pillar while mining the ultra-close lower panel using longwall top coal caving

作     者：Guorui Feng Pengfei Wang Guorui Feng;Pengfei Wang

作者机构：College of Mining EngineeringTaiyuan University of TechnologyTaiyuan 030024China 

出 版 物：《International Journal of Mining Science and Technology》 (矿业科学技术学报（英文版）)

年 卷 期：2020年第30卷第1期

页      面：55-61页

核心收录：

学科分类：081901[工学-采矿工程] 0819[工学-矿业工程] 0709[理学-地质学] 0808[工学-电气工程] 08[工学] 0818[工学-地质资源与地质工程] 0708[理学-地球物理学] 0807[工学-动力工程及工程热物理] 0815[工学-水利工程] 0813[工学-建筑学] 0814[工学-土木工程] 

基　　金：This study was funded by the National Natural Science Foundation for Young Scientists of China(No.51804209) National Natural Science Foundation of China-Shanxi Joint Fund for Coal-Based Low-Carbon Technology(No.U1710258) Applied Basic Research Programs,Science and Technology Foundation for Youths of Shanxi Province,China(No.201801D221363). 

主　　题：Simulation Remnant coal pillars Ultra-close Dirt band Longwall top coal caving 

摘      要：With the depletion of easily minable coal seams,less favorable reserves under adverse conditions have to be mined out to meet the market demand.Due to some historical reasons,large amount of remnant coal was left unrecovered.One such case history occurred with the remnant rectangular stripe coal pillars using partial extraction method at Guandi Mine,Shanxi Province,China.The challenge that the coal mine was facing was that there is an ultra-close coal seam right under it with an only 0.8–1.5 m sandstone dirt band in between.The simulation study was carried out to investigate the simultaneous recovery of upper remnant coal pillars while mining the ultra-close lower panel using longwall top coal caving(LTCC).The remnant coal pillar was induced to cave in as top coal in LTCC system.Physical modelling shows that the coal pillars are the abutments of the stress arch structure formed within the overburden strata.The stability of overhanging roof strata highly depends on the stability of the remnant coal pillars.And the gob development(roof strata cave-in)is intermittent with the cave-in of these coal pillars and the sandstone dirt band.FLAC3D numerical modelling shows that the multi-seam interaction has a significant influence on mining-induced stress environment for mining of lower panels.The pattern of the stress evolution on the coal pillars with the advance of the lower working face was found.It is demonstrated that the stress relief of a remnant coal pillar enhances the caveability of the pillars and sandstone dirt band below.