偃龙矿区奥陶系强岩溶含水层底板注浆改造技术

偃龙矿区地处豫西地区,矿井深部开采二1 煤层受奥陶系强含水层岩溶裂隙水威胁,奥灰水压不断增高,煤层底板构造发育、隔水层不稳定等突水因素影响了安全回采。通过水文地质资料分析与瞬变电磁技术进行底板富水性探测,建立了底板注浆改造深度精确计算模型,提出了偃龙矿区二1 煤层底板注浆改造水害防治技术,并进行了工业性试验。结果表明:12061 工作面底板分布有 3 种类型富水异常区,富水异常区域岩层节理、裂隙较为发育, 异常区覆盖工作面底板大部,工作面底板存在突水危险性;菱形钻孔布置有利于减小孔间距,最终确定底板注浆改造深度为 65 m、注浆压力为 9 MPa 与注浆扩散半径为 25 m,对太原组下段及奥陶系灰岩含水层注浆变含水层为相对隔水层,切断了底板奥陶系灰岩含水层与二1 煤层的水力联系;底板注浆封堵后,检验孔水量不大于 10 m³ / h,钻孔孔壁光滑,原 5 个富水异常区消失,注浆改造效果显著。

Grouting Transformation Technology of Ordovician Strong Karst Aquifer Floor in Yanlong Mining Area

Yanlong mining area is located in the west of Henan Province. In deep mining,No. 2 coal seam is threatened by karst fissure water of Ordovician strong aquifer,its mining safety is affected by increasing water pressure in the Ordovician limestone,the structure development of coal seam floor,the instability of water-barrier,etc. Based on the analysis of hydrogeological data and detection of water-rich floor by transient electromagnetic technology,the accurate calculation model of correction floor grouting depth was established,and the water disaster prevention technology of floor grouting reconstruction of No. 2 coal seam in Yanlong mining area was put forward,besides that,the industrial test was carried out. The results showed that three types of abnormal water-rich areas were in 12061 working face floor,where rock joints and fractures were more developed. The abnormal water-rich areas covered most of the working face floor,where water inrush could occur. The rhomboid borehole arrangement was beneficial to reduce the hole-spacing. The final floor grouting transformation depth was 65 m,the grouting pressure 9 MPa,the grouting diffusion radius 25 m. The aquifers of Ordovician limestone and the lower section of Taiyuan Formation could become a relative water barrier by grouting,which cut off the hydraulic connection between the floor Ordovician limestone aquifer and No. 2 coal seam. After floor was grouted,the water yield of the test hole was no more than 10 m ³ / h,the borehole wall was smooth,the original five abnormal water-rich areas disappeared,and the grouting transformation effect was remarkable.