摘要
冻土层季节性冻融过程会对地下水的渗流量、渗流方向和速度产生重要影响,进而导致冻土地区具有独特的地下水运移理论和机制.为了研究五九煤田胜利煤矿冻土地区矿井涌水来源及补给特征,采用水化学分析及13C、14C、18O、D4种环境同位素相结合的方法,分析矿井水的水化学特征及同位素分布特征,明确矿井涌水来源.通过对7组水样的试验研究发现:第四系水、第四系永冻层消融水、矿井水、基岩水均起源于大气降水,地表水、第四系水接受大气降水补给较快,基岩裂隙水、第四系永冻层消融水接受浅层第四系水的微量补给;采空区内黄铁矿氧化量较大,存在溶解少量瓦斯中CO2的可能性,导致采空区积水中13C富集;矿井水中地表水和第四系水入渗量较小,表明第四系永冻层隔水性能良好.研究结果与实际情况相符,不仅为胜利矿水害防治提供依据,还为冻土地区类似矿井水源判别提供借鉴.
Abstract
This paper takes the frozen soil area of Shengli Coal Mine in Wujiu Coalfield as the research object,and studies the source and supply characteristics of mine water in the frozen soil area.Seven groups of representative water samples selected from the field are studied utilizing hydrochemical analysis and four environmental isotopes of 13C,14C,D,and 18O.The content of each ion is determined by hydrochemical analysis,and the types of water samples are preliminarily classified.Then,the 11 indexes of hydrochemistry are reduced by principal component analysis,and the first two representative main factors are selected for subsequent hydrochemical analysis.The results show that surface water,Quaternary water,bedrock water,and goaf water cannot be clustered from the perspective of hydrochemistry.It is difficult to identify water sources by simple hydrochemical indicators,and it is still necessary to combine environmental isotopes for comprehensive analysis.The distribution characteristics and carbon isotope anomalies of 13C,14C,D,and 18O are analyzed to clarify the source and recharge characteristics of mine water.The results show that the identification of groundwater source is not obvious by 13C analysis alone,and D can be used as the identification mark of roof bedrock fissure water and Quaternary water and has good consistency with 18O,but the reliability is not as good as 14C.Surface water and Quaternary water receive rapid recharge from atmospheric precipitation,while bedrock fissure water and Quaternary permafrost ablation water receive trace recharge from shallow Quaternary water.The water supply of the mine is greatly affected by seasonality.The Quaternary seasonal frozen soil with shallow buried depth in summer is thawed,and the thawed water,surface water,and Quaternary water flow into the mine along the fissure.In winter,the temperature decreases,and the Quaternary permafrost fissures freeze again,re-forming a stable aquifuge and blocking the upper water into the mine;the average mixing ratios of Quaternary water in bedrock water(SLMK-6)and mine water(SLMK-4)are 17.14％and 11.50％,respectively,and the average mixing ratios of surface water are 9.48％and 1.57％,respectively.The research results are consistent with the actual situation,which provides a basis for the prevention and control of water disasters in Shengli Mine,and also provides a reference for the identification of similar mine water sources in permafrost regions.
维普
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