河流下多煤层开采安全性及保护技术

Safety and protection technology of multi-coal seam mining under river

我国新疆地区干旱缺水,艾维尔沟河作为新疆一条具有重要地理特征和环境影响的河流,其对于流经区域的经济、生态都具有重要意义,因此在艾维尔沟河下进行煤炭开采时,既要保证矿井安全也要保证河流的正常使用。采用理论分析、数值模拟等方法对河流下多煤层开采安全性及河流保护技术进行研究,通过理论计算得到多煤层开采条件下,覆岩导水裂隙带发育高度(11401工作面为41.9 m、1502工作面为110 m、11401工作面为113.8 m)并绘制剖面示意图;同时,采用数值模拟方法对覆岩导水裂缝发育形态及高度进行确定,最终基于导水裂隙带高度(117.8 m)与最小煤层埋藏深度(191.5 m)的相互关系,确定河流下开采是安全的可行的。在保证河流下煤层安全开采的前提下,通过分析离层注浆原理,并结合采动影响特征参数及工程现场,提出了以离层注浆为主,河道防渗及优化开采设计为辅的多手段对采动影响范围内地表特定目标的精准保护技术。根据实际采矿地质条件,采用概率积分法计算试采工作面开采前后河道位置处地表移动变形,计算结果显示:采用离层注浆精准保护技术后,河道的最大水平变形值(2 mm/m)未超出允许坝体的极限变形值(2.5 mm/m),所以采用离层注浆精准保护技术可以实现,井下安全开采的同时,保证河道的正常使用。通过对河流下多煤层开采的安全性及保护技术的分析研究,为矿山绿色开采提供参考和借鉴。

China’s Xinjiang region is drought and water shortage.As a river with important geographical characteristics and environmental impact in Xinjiang,the Aiweiergou River is of great significance to the economy and ecology of the region.Therefore,when coal mining is carried out under the Aiweiergou River,it is necessary to ensure the safety of the mine and the normal use of the river.The safety of multi-coal seam mining and river protection technology under rivers are studied by means of theoretical analysis and numerical simulation.Under the condition of multi-coal seam mining,the development height of overburden water-conducting fracture zone(11401 working face is 41.9 m,1502 working face is 110 m,11401 working face is 113.8 m)is obtained by theoretical calculation,and the profile diagram is drawn.At the same time,the numerical simulation method is used to determine the development form and height of the water-conducting fracture in the overburden rock.Finally,based on the relationship between the height of the wa-ter-conducting fracture zone(117.8 m)and the minimum coal seam burial depth(191.5 m),it is determined that the mining under the river is safe and feasible.Under the premise of ensuring the safe mining of coal seams under rivers,by analyzing the principle of separation grouting,combined with the characteristic parameters of mining influence and the engineering site,a multi-means based on separation grouting is proposed,supplemented by river seepage prevention and optimized mining design.Precise protection technology for specific surface targets within the scope of mining influ-ence.According to the actual mining geological conditions,the probability integral method is used to calculate the sur-face movement and deformation at the river channel position before and after the mining of the test mining face.The calculation results show that the maximum horizontal deformation value(2 mm/m)of the river channel does not ex-ceed the allowable limit deformation value(2.5 mm/m)of the dam body after the precise protection technology of separation grouting is adopted.Therefore,the precise protection technology of separation grouting can be realized,and the normal use of the river channel can be ensured while the underground mining is safe.Through the analysis and re-search on the safety and protection technology of multi-seam mining under rivers,it provides reference for green min-ing.