珊溪水库混凝土面板堆石坝施工期坝体排水

珊溪水库混凝土面板堆石坝由于施工期坝体反向水头较大，而垫层抗反向渗流能力强，如不采取适当的排水措施，有可能发生反向渗透水流破坏垫层及其固坡砂浆甚至混凝土面板的重大事故。为此，中国水利水电第十二工程局采取在两岸高边坡的合适位置设截水沟并结合道路排水沟将部分地表水引入基坑，在坝体内设反向排水钢管自由排水至趾板上游集水坑，用泵常年抽集水坑水等措施，解决了施工坝体反渗问题。经监测，大坝整体运行情况良好。

Drainage in the body of the Sanxi concrete face rockfill dam during construction period

Because of high reversal water head for the dam body and weak anti reversal seepage capacity during the construction period, the concrete face rockfill dam for the Sanxi Reservoir should take proper drainage measures to control probable failures caused by the reversal seepage flow. For this reason, the China Water Conservancy and Hydropower Engineering Bureau 12 has adopted the following measures to solve the reversal seepage flow during the construction period: arranging cutoff ditches in proper positions in the high side slopes of two banks to drain the surface water our of the foundation pit, using pump to lift water from the sump pit, setting up the reversal drainage steel pipe in dam body to drain water to the upstream sump pit of the plinth. According to the observation, the operation of the dam is good.