松散承压含水层水文地质参数分区及水流场数值模拟

摘要

为了揭示华北型煤田松散承压含水层水文地质参数及其对地下水流数值模拟的意义，以安徽淮北煤田宿南矿区祁东煤矿松散层承压第四含水层（简称“四含”）为研究示范，对多个影响因素综合分析，采用层次分析－模糊综合评价法，对研究区四含水文地质参数进行分区，合理确定各分区的水文地质参数，并用于采煤情景下地下水流动态数值模拟。数值模拟结果表明：祁东煤矿2008—2012年浅部煤层开采过程中四含地下水流场没有明显改变，但南北分区水头差逐年增大，地下水流向始终从南向北，而且在井田北部水力梯度逐渐减小，在井田南部水力梯度逐渐增大，南北区以倾角为60°～70°、断距为10～320 m的魏庙断层为分界线，基岩中大倾角与大落差断层的出现是引起上覆松散承压含水层水力梯度异常的根本原因。%In order to study hydrogeological parameters of unconsolidated confined aquifer of North China type coal field and its significance to groundwater numerical simulation,the fourth aquifer of the Quarternary (4th aquifer)in Qidong coal mine,Sunan mining area,Huaibei coal field,Anhui Province,is studied as an exam-ple.Based on the hierarchical analysis-fuzzy comprehensive analysis method,the study area is divided into ten divisions under hydrogeological parameters of 4th aquifer.The hydrogeological parameters of each division are properly determined,which are used for dynamic numerical simulation of groundwater flow under mining cir-cumstances.The results of numerical simulation show that the variation of groundwater flow field is unconspicu-ous in the process of mining of shallow coal seam from 2008 to 2012 in Qidong coal mine,but the differences of groundwater level between the north and the south increases year by year;therefore,groundwater always flows from the south to the north,which hydraulic gradient decreases in the north and increases in the south gradual-ly.The results also show that the decrease zone and the increase zone of hydraulic gradients are separated by the Weimao fault with a dip of 60-70 degree and a slip of 10-320 meters.It is concluded that a fault with great dip and slip in the bedrock are keys to hydraulic gradient anomaly in the overlying unconsolidated confined aqui-fer.