The Effection of Key Strata on Protection for Excavation the Steep-inclined Under-protecting Layer
The movement model of over-burden stratum was different between steep-inclined and flat seam after the exploitation of coal seam because of the impact of key strata. Taking oblique workface of under-protecting strata in a mine as an example, the load expression of the hard roof strata on oblique working face and the supporting load from filling were fixed, and this paper ascertained the key strata in over-burden stratum and calculated the interval of roof breaking after exploitation of the coal seam depending on key strata theory and using finite numerical simulation. The characteristic of movement of stratum was analyzed. Finally, the influence of the movement of key strata on the protecting scope was analyzed after the exploitation of protecting seam from the movement of stratum and the flow of gas. The research indicated the key strata in the stratum was cherty limestone whose hemstitch to the coal seam was 17 m and its first breaking interval was about 30 m. Before the breaking of the key strata, there was inconspicuous distortion of superincumbent stratum and the pressure of protected coal seam couldn’t release. After the breaking of the key strata, the distortion and fissures of superincumbent stratum increased. The gas in protected coal seam could give off sufficiently from upside of incline. Meanwhile, because of the filling of caving recrement in the underneath of incline, the distortion of stratum was inconspicuous and the gas couldn’t release here. The protecting effect of protecting strata increased gradually, and the protecting scope in the upside of incline was larger than in the bottom of incline.
FAN Xiao-gang WANG Hong-tu Yuan Zhi-gang
Key Lab.For the Exploitation of Southwestern Resources & the Environmental Disaster Control Engineering, Ministry of Education, Chongqing University, Chongqing, China
国际会议
International Mining Forum 2010(2010年国际采矿论坛 IMF 2010)
合肥
英文
106-109
2010-09-20（万方平台首次上网日期，不代表论文的发表时间）