水化学损伤作用下三山岛金矿渗流场特征分析

Analysis of Characteristics of Seepage Field in Sanshandao Island Gold Mine under the Action of Water Chemical Damage

三山岛金矿在深部开采过程中面临大范围的围岩渗水和涌水问题,作为海底开采矿山,研究渗水规律和涌水特征对于保证开采安全极为重要。通过矿区多区域多中段的涌水量监测分析,揭示出矿坑涌水量的动态规律,并对矿区-510 m至-725 m水平15个代表性水样采集点的地下水化学成分进行分析。结果表明该矿区地下水主要为Cl-Na型水,矿化度化验呈现高矿化咸水特征,地下水对岩体的化学损伤会影响到深部开采的安全。进一步采用FLAC3D对三山岛采区进行模拟开采,分析开采过程中渗流场的分布特征。结果显示矿区孔隙水压力变化范围主要集中在矿体开挖区域,渗流场的变化范围已经扩展到F3断层,断层周围孔隙水压力、渗透压力变化梯度较大,形成高渗透压力,在开采过程中需要进行堵水和重点防护。

There are large range of water seepage and inflow in surrounding rock mass of tunnels during deep mining of Sanshandao gold mine. As the undersea mining,it is necessary to find the rule and feature of water seepage and inflow for ensuring the safe mining. Through analyzing monitoring results of water inflow in multi-level areas,the dynamic law of water inflow in the mine is revealed. Meanwhile,the chemical component of mine water from 15 representative water samples in the range of- 510 m to- 725 m is analyzed. It is found out that the underground water is mainly Cl-Na water. In mineralization property,it belongs to high-salinity saline water. And the chemical damage of rock mass lead by high-salinity water will affect the stability of deep stoping. Numerical simulation by the software FLAC3 Dis conducted on deep mining of Sanshandao gold mine to analyze the distribution characteristics of water seepage field. The result shows that the variation of pore water pressure mainly occur in excavation areas. In addition,the variations of water seepage field have already expanded into F3 fault area in which the variation gradient of pore water pressure and seepage pressure are great,which forms high seepage pressure. Therefore,water plugging and intensive reinforcement are needed in the mining process.