含断层富水露天矿超前疏干条件下渗流场演化规律研究

Study on evolution law of seepage field under the condition of advance drainage in water-rich open-pit mine with fault layer

针对含断层富水露天矿超前疏干问题,以内蒙古东北部某富水露天矿为背景,基于GMS建立复杂地质实体模型,采用Lak3-Package模块设定各阶段矿山形态进行地下水模拟;预测了不同阶段的最大人工抽采水量,并研究了隔水断层由于剥离和降水逐渐导水的规律。研究表明:第1阶段降深至+645 m所需人工最大抽采量为1200 m3/d,第2阶段降深至+600 m所需人工最大抽采量为1.10万m3/d,第3阶段降深至+540 m最大抽采量为5.82万m3/d,最终降深至+480 m为9.82万m3/d;在第2阶段降深至+600 m抽采量达到1.10万m3/d时隔水断层因两侧水头差的增加使渗透压升高导致断层逐渐导水,在抽采量达到1.80万m3/d时断层变为导水断层。

Aiming at the problem of advance drainage of water rich open-pit mine with faults,taking a water rich open-pit mine in Northeast Inner Mongolia as the background,a complex geological entity model is established based on GMS,and the lak3 package module is used to set the mine morphology at each stage for groundwater simulation;The maximum artificial pumping water volume in different stages is predicted,and the law of water diversion gradually due to stripping and precipitation of water separation fault is studied.The research shows that the maximum manual extraction volume required for the first stage of drawdown to+645 m is 1200 m3/d,the second stage of drawdown to+600 m is 11000 m3/d,the third stage of drawdown to+540 m is 58200 m3/d,and the final drawdown to+480m is 98200 m3/d;In the second stage,when the drawdown reaches+600 m and the extraction volume reaches 11000 m3/d,the seepage pressure of the impermeable fault increases due to the increase of the head difference on both sides,resulting in the gradual water diversion of the fault.When the extraction volume reaches 18000 m3/d,the fault becomes a water diversion fault.