构皮滩水电站岩溶坝基的渗流监测

构皮滩水电站防渗帷幕线上存在复杂的岩溶系统。针对该种岩溶坝址,设计采用了渗压计、测压管和量水堰等组合形式的渗流监测系统,对坝基渗流进行全方位监测。水库蓄水期,坝基渗透压力与库水位呈明显的线性关系,但最大渗透压力增加值仅为库水位上升值的20％左右;水库蓄水完成后,坝基渗透压力与库水位的变化无明显关联。监测成果表明,工程防渗帷幕及岩溶封堵后整体防渗效果明显。监测系统为评价工程安全提供了可靠的科学依据。

Seepage Monitoring for the Karst Dam Foundation of Goupitan Hydropower Station

Complex karst system was found in the impervious curtain line of Goupitan Hydropower Station. In view of the karst dam site, we designed and adopted a seepage surveillance system including osmometer, piezometer tubes, measuring weirs and other measures to comprehensively monitor the dam foundation. During the reservoir impoundment, the osmotic pressure of dam foundation has an obvious linear relationship with water level, but the maximum increase of osmotic pressure is only about 20% of that of reservoir water level. After the impoundment, the seepage pressure of dam foundation has no significant relevance with the reservoir water level. Monitoring results show that the overall effect of impervious curtain and karst blocking is obvious. The surveillance system provides a reliable scientific basis for evaluating the project safety.