强富水弱胶结型底板砂岩水疏降优化技术研究

Study on drainage optimization technology of strong water abundance and weak cementation floor sandstone water

宁东煤田主要赋存侏罗系煤层,延安组宝塔山砂岩含水层是侏罗系下组煤的底板,具有富水性强、静储量大以及胶结性差的特点,是影响下组煤开采的主要充水水源。新上海一号煤矿即将开采的十八煤一分区底板隔水层较薄、带压程度较高,突水系数大于0.1MPa/m,均属于突水危险区,本文以新上海一号煤矿为研究区,在宝塔山砂岩含水层水文地质条件探查和井下放水试验的基础上,开展水文地质特征研究,通过构建地下水流数值模型对宝塔山砂岩疏降可行性进行论证,建立疏降管理模型,最终结合十八煤一分区开采布局,提出最优疏放管理方案,预计疏放水299.358万m^(3),比未进行地下水疏降优化管理设计预计疏放水量减少了188.242万m^(3)。在保护矿井水资源的同时,降低了生产成本,研究可为今后类似条件下的强富水弱胶结型底板砂岩水疏放水工作提供一定的借鉴作用。

The main coal seam in Ningdong coalfield is Jurassic coal seam.The Baotashan sandstone aquifer of the Yan'an Formation is the floor of the lower Jurassic coal group,which has the characteristics of strong water abundance,large static reserves and poor cementation.It is the main water-filling source affecting the mining of the lower coal group.The new Shanghai No.1 coal mine is about to be mined.The floor aquifuge of No.1 partition of No.18 coal seam is thin,the pressure is high,and the water outburst coefficient is greater than 0.1 MPa/m,all of which belong to the water outburst danger zone.This paper took the No.1 coal mine of the new Shanghai as the research area.Based on the hydrogeological conditions exploration and underground water discharge test of the sandstone aquifer in the Baota Mountain,the hydrogeological characteristics were studied.The feasibility of the sandstone dewatering in the Baota Mountain was demonstrated by constructing the groundwater flow numerical model,and the dewatering management model was established.Finally,combined with the mining layout of the No.1 partition of No.18 coal seam,the optimal dewatering management scheme was proposed,and the drainage water was expected to be 2.99358 million m^(3).Compared with the design of groundwater drainage optimization management,it was estimated that the amount of drainage water was reduced by 1.88242 million m^(3).While protecting the mine water resources,the production cost was reduced.The research could provide some reference for the drainage of sandstone water in strong water abundance and weak cementation floor under similar conditions in the future.