急倾斜中厚煤层长壁综采工作面覆岩运移规律

急倾斜煤层综采工作面"支架-围岩"系统动态稳定性控制难度大,而顶板的行为状态会直接影响该系统稳定性,从而制约该类煤层高效机械化生产,故研究急倾斜中厚煤层长壁综采工作面覆岩运移规律十分必要.综合采用相似材料试验法、理论分析法,研究分析工作面覆岩破坏及矿压分布、演化规律.研究结果表明,急倾斜中厚煤层综采工作面上、下端头顶板...

Overlying strata migration law of longwall fully mechanized mining face with steely inclined medium-thickness coal seam

It is difficult to control the dynamic stability of“support-surrounding rock”system in fully mechanized working face of steep coal seam,and the roof state will directly affect the stability of the system,thus restricting the efficient production of this kind of coal seam.Therefore,it is necessary to study the overlying strata migration law of longwall fully mechanized working face with steep medium-thick coal seam.By using similar material simulation test and theoretical analysis method,the failure law of overburden rock and the distribution law of ground pressure are studied.The results show that the upper and lower caving forms of fully mechanized mining face in steep medium-thick coal seam are in the shape of acute triangle and obtuse triangle respectively,and the collapsed roof will form ladder-shaped rock beam;the central part of goaf near the coal wall forms open area,and with the increase of the distance from the coal wall,the amount and compaction of gangue in goaf increases,and the accumulation form becomes more uniform;the ground pressure of the working face presents asymmetric distribution,which is strong in the middle and upper part;the working face’s first weighting step distance of is 25 m,the average periodic weighting step distance is 9.22 m,and the average support resistance is 3453 kN and 2682.8 kN respectively during weighting and normal condition.