徐州东部废弃矿井地下水流场演化模拟初探

以徐州东部废弃矿井为例，太原组灰岩含水层为研究对象，通过建立废弃矿井地区地下水流系统模型，运用数值模拟技术对区域地下水流场演变过程进行研究，揭示矿井废弃地区地下水流场演化的一般规律为:煤矿关闭前，为满足生产生活需要，矿井进行大量排水、抽水工作，矿区形成若干降落漏斗，如位于矿区西部的青山泉煤矿和北部的韩桥煤矿内均存在大面积降落漏斗，中心水位低于-25 m。受水力梯度影响，地下水向低洼的矿坑处汇集，原生地下水流系统遭到破坏。矿井闭坑后，原有排水系统全部停止工作，地下水位缓慢回升，降落漏斗逐渐减小，根据模型模拟结果，发现水位回升速度随矿井关闭时间的增加而减慢:在矿井关闭第1年内，水位回升速度较大，为1.14 m/a；关闭第3年时，水位回升速度减少至0.165 m/a；矿井关闭10年时，地下水最高水位为-16.55 m，从关闭第3年至第10年的7年时间内，水位回升速度仅0.039 m/a，矿区地下水流系统得到恢复，模拟区最终形成自北向南的近似稳定的地下水径流场。

Numerical simulation of groundwater flow field evolution in abandoned mine in the east Xuzhou

Based on the study of the abandoned mine in the east of Xuzhou, the evolution of Taiyuan Formation Aquifer groundwater movement has been detected through the establishment of groundwater system model in abandoned mine area and the study of the evolution of regional groundwater dynamic field using numerical simulation technology. It can be seemed that before the coal mine closed it has to drain away a lot of groundwater for the use of living and producing. So in the diggings there are various cones of depression, such as Qingshanquan coal mine and Hanqiao coal mine whose groundwater levels are below minus 25 meters in the cone centers. After the mine closed, all the drainage systems stopped and the groundwater level rises slowly, as well as the scope of depression cones. The rate of the level raising has become more and more slowly since the mine closed according to the simulation. In the first year after the mine closed, the rate will be 1.14 meters per year. Two years later, the rate will drop to 0.165 meters per year. By the time the mine has been closed for 10 years, the top groundwater level will have reached minus 16.55 meters while the rate will have decreased to 0.039 meters per year. Groundwater system of the coal mine will regain to a stable flow field which is the north to the south.