八盘峡水电站坝址高矿化地下水质成因分析及防治对策研究

Study on Causes of Formation & Countermeasures of High Degree of Mineralization of Groundwater Quality in Hydroelectric Power Station of Bapanxia

水电站坝址区水-岩-坝系列间的相互作用易形成异常地下水,并可能对坝基混凝土产生腐蚀等破坏作用。该文以八盘峡水电站为例,对水电站坝址区近10多年来的地下水水质资料进行统计分析后,发现坝址左岸坡及河床左侧部位地下水质呈高矿化,综合分析认为坝址区蒸发岩中所含丰富的硫酸盐矿物是地下水中SO42-的主要物质来源,左岸的台地地形更有利于大气降雨、农业灌溉及居民生活用水的入渗补给,而排泄不畅及帷幕体接合欠佳造成的防渗缺陷使补给丰富的地下水在左岸坡汇集并进而影响到河床左侧有关坝段。最后,提出了相应的防治对策。

Interactions of the series of water-rock-dam are easy to form abnormal quality of groundwater. It may corrode the concrete of the dam foundation. This paper statistically analyses the groundwater quality data for recent more than ten years at hydroelectric power station of Bapanxia, and discovers the high degree of mineralization of groundwater quality in the left bank slope of dam site and the left part of river bed. It considers by analysis syntheticly that prolific sulfate minerals in evaporaing rock are the main material sources of SO4^2- in groundwater, and the mesa terrain of the left bank makes atmospheric precipitation, agriculture irrigation and domestic water recharge by infiltration favoringly. The not well drainage and limitations of anti-seepage curtain body make the groundwater which recharge rich merge at the left bank slope, and influence the left parts related. At last, it presents homologous prevention and cure countermeasures.