Abstract: After the completion of surge tank in Tianshengqiao Ⅱ hydropower station, derailment, blocking and other accidents often occurred when the gate of surge tank went down, so the modification was urgently needed. This paper introduced the design, construction difficulty and relevant solving method, worthy reference.

Key words: surge tank, emergency overhaul gate, technology modification, boring and planting steel bar, concrete demolishment

摘要： 天生桥二级电站调压井建成后，调压井闸门下落时常发生脱轨、卡槽等事故，需要改造。笔者介绍了改造的设计思路及施工中遇到的困难及解决方案，为其他同类型的改造施工提供详实的可借鉴的实践经验。

关键词: 调压井, 事故检修闸门, 技术改造, 钻孔植筋, 混凝土拆除