寒旱区井工煤矿开采与含水层失水协同分析模型构建及应用

针对寒旱草原区煤矿开采对地下水资源影响研究不足、评价方法定量程度不高等问题,文中以位于我国东北呼伦贝尔草原敏东井工矿为研究对象,通过分析井工煤矿开采引起的覆岩含水层失水特征,以地下水系统数值模拟软件为平台,提出将采煤形成的导水裂隙空间范围的处理成地下水系统的内部边界,以及调整不同开采期模型的初始水头,形成了敏东煤矿开采与含水层失水协同分析的数值模型构建方法。模拟分析得出研究区水均衡总量受大气降水控制明显,随着年降雨量增加水均衡总量增加,同时受到季节性冻土层隔水效应的影响,年均降雨入渗系数仅为0.12;煤层采动裂隙沟通的III含水层形成一般小于5m的水位降深,近地表的第四系Q含水层水位下降降深一般小于1m;地下水系统扰动程度指标E_q受矿井涌水(含水层地下水失水量)控制明显,矿井涌水量越大扰动程度E_q越高,2012年最大为9.8%,同时受大气降水补给影响,2013丰水年E_q减少至6.3%。

Synergistic model of underground coal mining associated groundwater system response in cold and arid grassland area

This research took Mindong underground coal mine in Hulun Buir Grassland area of Northeast China as the research object,by analyzing the water loss characteristics of the overlying aquifer caused by the mining of the underground coal mine,and using the groundwater numerical simulation software,we proposed that the spatial range of the water conducted fractured zone formed by mining is treated as the internal boundary of the groundwater system,and the models for initial water heads in different mining periods are adjusted to form the synergistic model of Mindong underground coal mining associated groundwater system response for collaborative analysis of mining and aquifer water loss.The model analysis shows that the total groundwater balance is obviously controlled by the precipitation,with the increase of annual rainfall,the total water balance increased.However,the average rainfall infiltration coefficient is only 0.12 because of the effect of water isolation by seasonal frozen soil layer.The water drawdown of III sandstone fissured aquifer is generally less than 5 m which fractured by coal mining,and the water drawdown of Q aquifer is lower than 1 m in the near surface.Moreover,the index E_q of the disturbance degree of the groundwater system is obviously controlled by the water inflow of the mine,the greater the water inflow is,the higher the disturbance degree E_q is.Meanwhile,it is affected by the recharge of meteoric water,the maximum was 9.8%in 2012,due to the large amount of precipitation in 2013,E_q was reduced to 6.3%.