疏降条件下宝塔山砂岩含水层突水风险性评价及排水系统能力校核

Evaluation of Water Inrush Risk in Baotashan Sandstone Aquifer under Drainage Conditions and Check of Drainage System Capacity

摘要: 新上海一号煤矿18煤底板宝塔山砂岩含水层厚度大、水压高，对煤层安全回采构成严重威胁。为评价疏降条件下底板突水危险性并优选疏放水方案，以18煤一分区及首采工作面为研究对象，设计了四种疏放水方案，采用数值模拟方法分析各方案下水位降深规律、突水系数演化特征，并利用大井法预测涌水量，同时结合矿井现有排水系统进行能力复核。结果表明：原始条件下宝塔山砂岩含水层平均突水系数为0.08 MPa/m，超过安全临界值0.06 MPa/m；随着疏放钻孔数量增加，水位降深逐步增大，突水系数小于0.06 MPa/m的安全区域范围不断扩大；四号方案效果最优，但二号方案在保证安全的前提下疏放水量较小、对排水系统压力相对适中。涌水量预测显示，二号方案下矿井正常涌水量增至765 m³/h，最大涌水量859.64 m³/h；现有排水系统中水仓容量及水泵正常排水能力不满足要求，需进行改扩建。综合考虑安全性与经济性，建议优先采用二号方案，并配套实施水仓扩容改造。研究成果可为类似水文地质条件下的深部煤层底板水害防治提供技术参考。

Abstract: The Baotashan Sandstone Aquifer underlying the No. 18 coal seam in the Xinshanghai No. 1 Coal Mine is characterized by large thickness and high water pressure, posing a serious threat to safe coal mining. To evaluate the risk of floor water inrush under depressurization conditions and to optimize the water drainage scheme, the first mining district of the No. 18 coal seam and its initial working face were taken as the research objects. Four drainage schemes were designed. Numerical simulation was adopted to analyze the drawdown patterns and evolution characteristics of the water inrush coefficient under each scheme, and the big well method was used to predict the water inflow. Meanwhile, the capacity of the existing mine drainage system was re-evaluated. The results show that under natural conditions, the average water inrush coefficient of the Baotashan Sandstone Aquifer is 0.08 MPa/m, exceeding the safety threshold of 0.06 MPa/m. With an increasing number of drainage boreholes, the drawdown gradually increases, and the safe area where the water inrush coefficient is below 0.06 MPa/m expands continuously. Scheme 4 achieves the best depressurization effect, but Scheme 2 has a relatively smaller drainage volume while ensuring safety, imposing moderate pressure on the drainage system. The water inflow prediction indicates that under Scheme 2, the normal mine water inflow increases to 765 m³/h, and the maximum water inflow reaches 859.64 m³/h. The existing drainage system does not meet the requirements in terms of sump capacity and normal pumping capacity, necessitating expansion and renovation. Considering both safety and economy, Scheme 2 is recommended as the priority, together with the implementation of sump capacity expansion. The research results can provide technical reference for the prevention and control of floor water hazards in deep coal seams under similar hydrogeological conditions.