白市水电站渗漏处理措施研究

Study on seepage treatment measures for Baishi Hydropower Station

白市水电站大坝为碾压混凝土重力坝,蓄水后结构缝漏水。因工程建设过程中停工时间过长,形成新的强约束区,产生大量次生裂缝。针对不同的渗漏通道,探索了采用化学灌浆处理,同时根据漏水量的大小、渗水部位、渗压高低,选用聚氨酯作灌浆浆材,取得了预期的防渗效果。在此基础上,提出了在坝体上游面新的强约束区主动增设表层防渗层及在坝块高差过大止水易破坏的结构缝上游端增设嵌缝止水结构的设想,以期在类似工程中应用,取得良好的经济效益。

The dam of Baishi Hydropower Station is a roller compacted concrete gravity dam,of which seepage occurs from the structural joint after the impoundment of the reservoir. Because of a long period of suspension of the construction,new strong andnew restrained area is created therein with a large amount of secondary cracks. For different seepage paths,chemical grouting is exploratorily adopted,while polyurethane is selected as the grouting material in accordance with the amount of leakage,seepage location and seepage pressure,and then the expected effect is obtained. On the basis of this,it is proposed to initiatively add both a surface anti-seepage layer upon the new restrained area of the upstream face of the dam and a calking sealing structure to the water seal of the upstream end of the structural joint that is prone to be damaged due to the over-larged height difference in between the dam blacks. It is expected to be applied to the similar project and get better economic efficiency as well.