Abstract: Scouring of foundation of underwater structures in the downstream energy dissipation area of a hydropower station is common. Combined with Zilanba hydropower project, based on analysis of cause reasons for scouring, the rehabilitation scheme is put forward. By pouring of underwater non-dispersing concrete, the cavity caused by scouring in foundation is eliminated. As well, the remaining downstream cofferdam core wall and the deposit of sand and gravel are removed to improve the flow pattern. The treatment scheme is effective which eliminated the risks caused by foundation scouring.

Key words: underwater structures, foundation scouring, underwater non-dispersing concrete, ton bag, precast slab

摘要： 水电站下游消能区水下建筑物基础淘刷是水工常见病害之一。针对紫兰坝水电站下游消能区基础淘刷情况，分析基础遭淘刷原因和对水电站的安全影响，研究制定修复处理方案。采用水下不分散混凝土浇筑回填方法，解决基础淘刷悬空的重大问题，同时对下游残留围堰心墙和砂石料堆积体进行拆除疏浚，改善下泄水流流态，有效排除水下建筑物基础淘刷带来的结构安全隐患。

关键词: 水下建筑物, 基础淘刷, 水下不分散混凝土, 吨袋, 预制板