Simulation study on the evolution of the overlying strata fractures and air-leaking passage under repeated mining of shallow buried coal seams
YU Minggao
TENG Fei
CHU Tingxiang
CHAO Jiangkun
LI Pin
Abstract：In order to study how the surface air leakage caused by repeated mining at shallow buried and contiguous coal seam group influence the spontaneous combustion of coal in goaf.Based on ShenDong mining area of western China,plastic zoned、porosity and displacement of overlying strata at different extraction stages,where caculated by FLAC3D.The results show that:(1)maximun crack height is 130 m after the mining of upper seam,the height do not connect the surface;maxinmm crack height has devoloped to 162 m and connected the surface after the mining of underlying seam.There is a' U' shape of strata fracture distribution.(2) There is an separation area at around 62 m over upper coal face after the mining of upper coal face,the deflection of strata under separation area is 1.75 ～ 4 m,the deflection of strata above the separation area is 0.25 ～ 1 m.With the mining of undelying seam,the separation area and the deflection of the strata has further developed.(3) At the same stage of extraction,the porosity rate of both sides of strata is bigger than that of the middle of strata.The porosity of strata has further developed with the mining of undelying seam.
Keywords：repeated miningcontiguous coal seam group of shallow buriedoverlying strata fractureprosity
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 1-7 )