Characteristics of phreatic water resources loss in the northern foot of Tianshan Mountain under the influence of coal mining
XU Feng ,JIN Dewu ,SHI Lei ,WANG Shidong ,HE Yuan ,HUANG Huan
天山博格达峰北麓山前丘陵区潜水资源为当地工农业以及居民生活用水的重要水源,针对该区日益严重的潜水资源流失问题,以铁厂沟河流域潜水含水层为研究对象,采用水文地质测绘、地面高密度直流电法勘探、水文地质钻探以及数值模拟等手段,对沿铁厂沟河流域潜水含水层空间展布与富水性特征、潜水资源的流失途径及流失量进行了研究与分析。结果表明:铁厂沟河与八道湾向斜北翼煤系地层交汇区第四系冲洪积层呈南(上游)厚北(下游)薄的特征,松散层底界标高沿河流方向呈逐渐降低趋势,与山前沟流冲洪积厚度及空间形态特征基本一致;通过抽水试验获得该区潜水含水层单位涌水量q为0.146 L/(s·m),渗透系数K为0.233 m/d,含水层富水性中等;潜水流场以地表塌陷坑为中心呈现出典型的降落漏斗形态,结合塌陷坑内存在流水声现象,分析该塌陷坑区域存在沟通潜水含水层与井下采空区的集中通道;采用FEFLOW数值模拟计算塌陷坑处的潜水漏失量86 m3/h,与井下涌水量实测值基本吻合,进一步验证了第四系潜水通过塌陷坑区集中通道补给井下采空区,使得井下采空区涌水维持稳定;煤矿开采是引发铁厂沟河中下游流域潜水资源流失的主要原因,采动后形成的塌陷裂缝是潜水流失的主要通道,针对塌陷裂缝的工程治理是保护潜水资源的主要途径。
The water resources in the piedmont hilly area at the northern foot of the Bogda Peak in the Tianshan Mountains are an important source of water for local industry, agriculture and residents' domestic use. In view of the increasingly serious loss of water resources in this area, taking Tiechanggou River Basin phreatic water aquifer as the research object, the spatial distribution and water-rich characteristics of the phreatic aquifer along the Tiechanggou River Basin, the way and amount of phreatic resource loss were studied and analyzed by means of hydrogeological mapping, surface geophysical exploration, hydrogeological drilling, numerical simulation and other means. The results show that the Quaternary alluvial-proluvial layer in the coalbed formation intersection area of Tiechanggou River and Badaowan syncline is thick in the south (upstream) and thin in the north (downstream), and the floor elevation of the loose layer is gradually decreasing along the river direction, which is basically consistent with the characteristics of the gully flow in front of the mountain. The unit water inflow (q) of the aquifer in this area is 0.146 L/(s·m), the permeability coefficient (K) is 0.233 m/d, and the water richness of the aquifer is medium. The submerged flow field takes the surface collapse pit as the center and presents a typical falling funnel shape, and there is a concentrated channel between the groundwater aquifer and the underground gob in the subsidence pit area. FEFLOW numerical simulation was used to calculate the phreatic water leakage at the collapse pit, which was 86m3/h. This was basically consistent with the measured value of downhole water inflow. Coal mining is the main cause of the loss of diving resources in the middle and lower reaches of the Tiechanggou River. The collapsed cracks formed after mining are the main channels of the loss of diving resources. The engineering treatment of the collapsed cracks is the main way to protect the diving resources.
coal mining;loss of diving resources;underground goaf;collapse crack;FEFLOW numerical simulation
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会