黔中水利枢纽大坝左岸帷幕灌浆平洞处理措施及效果评价

Effect evaluation and measures on curtain grouting of adit located on the left bank of the dam of Qianzhong Hydraulic Project

岩溶地区筑坝建库,防渗处理是工程技术的重点、难点,处理结果的好坏将直接影响工程能否正常运行及发挥设计效益。针对黔中水利枢纽大坝左岸帷幕灌浆工程ZPD4灌浆平洞大型充沙溶洞的情况,拟定了3个处理方案进行比选,最后确定采取全部清除沙层回填混凝土方案。方案实施过程中出现了溶洞顶板跨度太大、顶部揭露的岩体破碎等问题,经研究采取调整处理方案和施工顺序等措施,从而确保了施工安全。

Seepage control is a critical and difficult part of dam construction in karst area, and its performance has a direct impact on normal operation and benefit generation of the project. Regarding curtain grouting conditions of large sand filled cavern of ZPD4 adit located on the left bank of Qianzhong Hydraulic Project, three options were compared, among which removal of entire sand layer that refilled by concrete was selected. However, problems were found such as large span of karst cave roof and rock fragmentation on the top, which had been solved by making adjustment and modification of construction sequence, so as to ensure safety during construction.