采空区下特厚煤层首采综放工作面顶板断裂的微震监测研究

Micro Seismic Monitoring Research on Roof Fracture at the First Fully Mechanized Mining Face in Special Thick Coal Seam Under Goaf

针对采空区下特厚煤层综放工作面采场矿压特征复杂、工程实例少的特点,以斜沟煤矿23103综放工作面为背景,采用高精度微震监测技术对其顶板断裂及其演化过程进行了研究。结果表明:该工作面高能量微震事件在煤壁前方80 m附近开始发生,且多分布在高位顶板(30~70 m),具有明显的周期性;高位顶板周期性断裂和下沉迫使低位顶板(0~30 m)在煤壁前方30 m附近发生持续性破裂;采空区微震事件分布在煤壁后方0~30 m范围内,且多集中在材料巷帮附近;在顶板70 m以上为8号煤采空区,无明显的微震事件。

In view of the characteristics of complex pressure features and lack of engineering examples at the first fully mecha-nized face in special thick seam under goaf, taking Xiegou Coal Mine 23103 fully-mechanized working face as the background,we use high-precision micro seismic monitoring technology to study the roof fracture and its evolution process. Results show thatthe high energy micro seismic events at coal face occur in front of the coal wall of 80 m, and the events distributed in the highroof （from 30 m to 70 in） have obvious periodicity; the periodic fracture and sinking of high roof make the low roof （0 to 30m） occur persistent rupture in front of the coal wall of 30 m; goaf micro seismic events are more distributed behind the coal wallwithin the scope of 0 to 30 m, and more focused on the material lane near to coal wall; No. 8 coal goal above the roof of 70 Inhas no obvious seismic events.