45. Water Seepage Analysis of a Seabed Metal Mine

For mining under surface water, the research of seepage characteristic is a preventive work for mine water problems. The determination and evolution of the proportions of different mine water sources can indicate undoubtedly the potential origination of inrushing waters and facilitate protecting fresh groundwater. Xinli Gold Mine is the largest seabed mine in China and, since its commissioning, has been faced with the problems of mine water inrush and fresh groundwater protection. This paper finds out the proportional relation among three kinds of sources of in-pit leakage waters at different depths of the Xinli Gold Mine through environmental isotope and hydro-chemical analysis, and considers that seawater and bedrock brine are the dominating components of which the seawater will replace the brine water gradually. Marine mud layers and fault gouge as good water-resistant layers may still allow, to some extent, water to penetrate them driven by head difference as a result of the dewatering of drifts, but this did not excessively destroy fresh groundwater resource currently. Results indicate a steady seepage field has formed in the mining area, which is an advantage for seepage simulation and inflow calculation.