滨海矿山矿坑涌水源识别与混合比研究

通过水化学和同位素分析，并利用主成分分析法（PCA）确定了三山岛金矿西山矿区井下巷道的涌水来源为海水、375-20（Mg）、淡水和320-7（Ca），其中375-20和320-7均为基岩水，但其水化学特征明显不同，前者是富Mg型基岩水，而后者是富Ca型基岩水。据此建立了巷道涌水的混合模型，在此基础上结合极大似然法计算得到巷道涌水混合比，分析其演化规律。研究表明：该方法能够有效识别涌水来源，并计算水样混合比；海水在各端元中占比最大，是混合水的主要成分，各期水样海水比例在50%左右波动；海水比例较高的中段为-510 m中段，在此中段处于1660和2230勘探线之间的水点，各期海水比例大于50%，尤其是510-2水样点，海水比例最高达到77%；淡水主要影响范围是-465 m及以上中段；F3断裂带受采动影响较大，其周围的水样点海水比例波动大，需加强对该断裂带的监测。

Study on Water Sources Identification and Mixing Ratios of Mine Water

Sanshandao gold mine is located in the Laizhou Bay， eastern China.Its north and west sides are bordering the Bohai sea， only the southeast side is connected to the land.The mining operations are below the sea level， so the sea water is the potential threat to the mine.In order to predict and prevent water inrush disaster， it is important to identify the mine water source and determine the mixing ratios.In view of the identification of water source in mine tunnel， domestic and foreign scholars have done a lot of research.At present， the methods of mine water source identification are neuron network method， based on entropy weight-fuzzy variable set theory， clustering analysis， distance discriminant analysis and Fisher discriminant method.These methods can make a good distinction for water with simple composition， and are only qualitative identification for the composition of the complex water source， and there is no quantitative determination of mixing ratios of the mine water.Based on hydrogeochemical and isotopic analysis， the method of principal component analysis （PCA） was used to identify the mine water sources （seawater， 375-20 Mg， freshwater and 320-7 Ca） of Sanshandao gold mine and established the mixing model of mine water.The 375-20 （Mg） and 320-7 （Ca） are both brine but have different hydrochemical characteristics.The 375-20 is rich in Mg and the 320-7 is rich in Ca.The first， the second and the third components of the PCA method explained 88% of the information of the water samples， so the water sample can be represented by these three principal components.The end-members mixing ratios were calculated by the maximum likelihood method and the evolution rules of mine water were analyzed according to the calculation results.Unlike the traditional method， the maximum likelihood method holds that the end-member concentration is not a fixed value， but a change in time and space， and the influence of mining on the end-member can be effectively reflected by this method.The research shows that the method can effectively identify the water sources and calculated the mixing ratios.The seawater is the main component of mixed water and for the entire mine the proportion of the seawater fluctuated around 50% every year， the proportion of 375-20（Mg） and freshwater fluctuated around 20% and the 320-7（Ca） flucated around 10%. At -510 m sublevel， the mine water has a high proportion of seawater. At most of the water sites which are located between the prospecting lines 1660 and 2230，the proportion of seawater are more than 50%， especially at 510-2， the highest proportion is 77%. The main range affected by fresh water is 465 m sublevel and above. F3 fault is greatly affected by the mining， and the proportion of seawater of sites around which fluctuate greatly， so the monitoring of F3 fault needs to be strengthened.