寒武系上段隔水性及在马陵山矿带压开采中的应用

Research on the impermeability of upper member of Cambrian and its application on coal mining above aquifer in Malingshan coalmine

煤层底板隔水岩层的结构、厚度是影响承压水上采煤安全性的重要因素。河南省局部地区缺失奥陶系,煤层开采受底板高承压寒武系石灰岩岩溶水突水威胁严重。以位于豫中矿区的马陵山煤矿为例,通过现场钻探查明了该矿煤层底板寒灰上段至少25 m厚度的含隔水层结构。以此为基础,评价了该层段的阻隔水能力,研究了基于GIS平台并利用寒灰上段的相对隔水性开展底板突水危险性评价的方法。应用研究成果,解放了马陵山矿约1 340万t的煤炭资源储量,并实现了近400万t煤炭的安全采出;同时,成功完成了该矿-350 m水平上车场进入寒灰上段垂深55.5m、320 m长巷道的施工。研究表明,将寒灰上段岩溶不发育段作为隔水层考虑更符合实际,并成功指导了马陵山矿的带压开采工作。

The structure and thickness of the floor aquifuge are important influencing factors for the safety mining above confined aquifer. Due to Ordovician strata missing in the certain areas of Henan Province, coalmines are often serious threatened by the floor Cambrian limestone Karst water inrush. The hydrogeological structure characteristics in the upper member with the thickness of at least 25 m of Cambrian limestone in Malingshan coalmine is detected in this paper, and then, the wa- ter-resisting-isolating capability of the upper Cambrian limestone is assessed. Subsequently, based on the GIS platform, the method of risk assessment for floor water inrush by using the relative imperme- ability of upper member of Cambrian limestone is studied. By adopting the research result, 13.4 million tons of coal resources in Malingshan coalmine are liberated and 4 million tons of coal resources are safety extracted and then, the shaft station at -350 m elevation is successful tunneled with the depth of 55.5 m and the length of 320 m into the upper member of Cambrian limestone. Owing to considering the existence of the relative aquifuge section locating in the upper member of Cambrian limestone, the result, which more tally with actual situation, has been successful applied in Malingshan coalmine for its coal mining practice above confined water with high pressure.