Abstract: Luzhu River inverted siphon in Qiandao Lake water distribution project has some construction difficulties, such as adverse geological condition and many influence factors of surrounding environment. In this paper, the original design and layout of inverted siphon are optimized. The optimization scheme raises the water supply steel pipe on the right bank by 5 m. Based on the structural stability and construction conditions, a comprehensive comparison and analysis of the original scheme and the optimized scheme are made. The results show that the optimization scheme is feasible and has obvious advantages, such as reducing the amount of excavation and backfill of 1.3×10⁵ m³, shortening the construction time by three months and better protection of environment.

Key words: inverted siphon, foundation pit, uneven settlement, optimization design

摘要： 杭州市千岛湖配水工程渌渚江倒虹吸段地质条件较差，周边影响因素较多。对倒虹吸管原设计布置方案进行了优化设计，将右岸台地段输水钢管抬高5 m，并从结构稳定性与施工条件对原方案与优化方案进行综合比较分析，认为优化方案可行且具备明显优势。优化方案较原设计方案土方开挖及回填量均减少13万m³，工期可减少3个月，且开挖料临时堆场规模减小，有利于环境保护。

关键词: 倒虹吸, 基坑, 不均匀沉降, 优化设计