关键词: 首采工作面, 初采阶段, 定向钻进, 水力压裂, 矿压显现, 坚硬顶板

Abstract: Aiming at the problems such as the difficulty of the roof collapse during the initial mining of the first mining working surface under the condition of hard roof plate, the 2102 working surface of Balassu Coal Mine is used as the research background, Using theoretical analysis and field experiments, the mechanical structure model of the first collapse of the working surface was established. The hydraulic fracturing comprehensive weakening treatment technology of directional long drill + short drill is proposed. The weakening effect of the roof after fracturing is comprehensively evaluated, and the characteristics of ore pressure during the initial mining period after fracturing of the first mining surface are analyzed and mastered. Studies have shown that: When hydraulic fracturing is not performed, the ceiling area of the roof plate is large, and the mechanical model calculates the initial collapse step distance of 77m. It is concluded that the working surface is reasonably hydraulic fracturing range vertical to 12.26m~23.43m, and the horizontal direction is within 30.8m; The maximum pressure of directional hydraulic fracturing reaches more than 26MPa, and the short drill fracturing reaches more than 52MPa, both of which show significant pressure drop, and the maximum drop reaches 26MPa; After fracturing, the peep effect of the hole is good, and the water outlet phenomenon of the adjacent hole is obvious. The ore pressure of the roof of the working surface is mainly manifested as the characteristics of frequent small pressure, and the initial pressure strength increases by 14.14% compared with the promotion of 30m. The synthesis shows that the effect of hydraulic fracturing is remarkable. Through the comprehensive three-dimensional advanced treatment technology system of "directional long drilling + conventional short drilling", the safe recovery during the initial mining of the 2102 working surface is realized, which provides a reference treatment method for the treatment of strong mineral pressure disasters in the initial mining stage of the working surface under similar conditions.