Evolution characteristics of mining-induced stress field of fully mechanized top-coal caving face based on in-situ stress

摘要

Considering the significance of in-situ stress on the mining-induced stress around the fully mechanized top-coal caving (FMTC) mining face, which has already become the most common mining method for thick coal seams.The hollow inclusion strain gauge method was used to test the in-situ stress of zhuxianzhuang coal mine, and then the in-situ stress field has been back analyzed based on the multi-objective constraints optimization method, whose results illustrate that the orientation of the maximum horizontal stress lies in N60°E to N75°E, the horizontal maximum principal stress mainly varies from -19 MPa in the west and north to-22.5 MPa in the east and south, the relative relationship among the maximum horizontal stress, minimum horizontal stress and vertical principal stress is: σHmax ＞σv ＞σHmin, the lateral pressure coefficient reaches 1.44, and the non-uniform coefficient of the horizontal stress ranges from 1.68 to 1.77.Finally, a numerical simulation model of FMTC working face was established with FLAC3d to study the mine-introduced stress distribution rules and its evolution process based on in-situ stress field.The magnitude and change regulation of maximum vertical stress Szz, maximum horizontal stress Syy and maximum shear stress Syz has been obtained, and the mining-induced vertical stress field can be divided into five stress zones, which is similar to other mechanized mining face but for the exact values and evolution characteristics.