超高水材料袋式长壁充填开采覆岩控制技术研究与应用

Study and application of overlying strata control technology in bag-type backfill longwall mining with super high-water content material

系统分析了超高水材料袋式充填开采采场覆岩结构的特点,得出了工作面支架需控岩层范围及其变化特征,揭示了长壁充填开采"支架-围岩"关系,明确了提高充填率是超高水材料袋式充填开采覆岩下沉控制的关键因素。结合亨健矿2515工作面充填开采地质与开采技术条件,开发并实施了隔板布置优化、采空区埋管补注浆充填、离层区打钻补注浆充填等充填率保障技术与工艺。现场实测结果表明,超高水材料袋式充填开采工作面矿压显现缓和、采场围岩破裂范围较小且能有效控制地表下沉:1工作面巷道顶底板最大移近量为258 mm,两帮最大移近量为183 mm,围岩变形较小;2微震监测系统表明,2515工作面超前破裂范围为20~30 m,围岩破裂高(深)度为顶板以上40 m至底板以下10 m,1个月后(推进距离60 m左右)已充填区域微震事件逐渐消失;3地表最大下沉量为265 mm,实测下沉系数为0.06。

After analyzing the features of coalface's wall rock structure in bag-type filling mining with super high-water content material systematically,the range and variation law of strata controlled by support in coal face were obtained,while the relationship between support and surrounding rock in backfill longwall mining was also revealed. In addition,it was confirmed that the key factors of control on overlying strata subsidence in bag-type backfill mining with super high-water content material was to increase filling rate. Combined with geological conditions and mining techniques atNo. 2515 backfill coal-face in Hengjian Coal Mine,several techniques and processes on guaranteeing filling rate,the optimization of separator-layout,burying pipes into goaf and drilling into separation area to replenish grouting filling were proposed and applied. The measured results show that the strata behaviors of coal-face is relaxed,while the range of coalface's wall rock rupture monitored becomes small in bag-type filling coal face with super high-water material,accordingly surface subsidence is also controlled effectively: 1 the deformation of surrounding rock is relatively small,while the maximum convergence of roadway roof-floor and sides is 258 mm and 183 mm respectively; 2 micro-seismic monitoring system shows that the range of No. 2515 advanced rupture is varied from 20 m to 30 m,while the height or depth of surrounding rock rupture is 40 m above roof to 10 m below floor,besides these micro-seismic events will disappearedgradually after one month with about 60 m of mining distance; 3 the maximum subsidence of surface is265 mm,while its actual measured subsidence coefficient is 0. 06.