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

BP. Energy outlook 2019 edition. London; 2019. Bai, 2018, Vertical stress and stability of interburden over an abandoned pillar working before upward mining: a case study, R Soc Open Sci, 5, 10.1098/rsos.180346 Ghabraie, 2016, Mechanism and prediction of ground surface subsidence due to multiple-seam longwall mining, 1 Zhang, 2016, Residual coal exploitation and its impact on sustainable development of the coal industry in China, Energy Policy, 96, 534, 10.1016/j.enpol.2016.06.033 Chen, 2016, Strip coal pillar design based on estimated surface subsidence in Eastern China, Rock Mech Rock Eng, 49, 3829, 10.1007/s00603-016-0988-y Gao, 2014, Study on the width of the non-elastic zone in inclined coal pillar for strip mining, Int J Rock Mech Min Sci, 72, 304, 10.1016/j.ijrmms.2014.09.013 Esterhuizen, 2010, Numerical model calibration for simulation coal pillars, gob and overburden response, 46 Chen, 2018, Extraction of the remnant coal pillar in regular and irregular shapes: a case study, J Loss Prev Process Ind, 55, 191, 10.1016/j.jlp.2018.06.012 Feng, 2019, Stability of gate roads next to an irregular yield pillar: a case study, Rock Mech Rock Eng, 52, 2741, 10.1007/s00603-018-1533-y Wang, 2017, A coupled macro- and meso-mechanical model for heterogeneous coal, Int J Rock Mech Min Sci, 94, 64, 10.1016/j.ijrmms.2017.03.002 Itasca Consulting Group Inc, 2018