一、概况桐庐县肖岭水库(中型)总干渠渠首过溪暗沟于1990年第15号强台风中被彻底冲毁,因直接影响到下游三万亩农田的灌溉和肖岭二、四级电站的发电效益,故急需及时修复。经现场踏勘分析后,认为原过溪暗沟处于溢洪道下消力池边是不安全可靠的,为此决定移位,改用倒虹吸方案(断面2×2m,Q_设=6.5m~3/S)。工程修复概算,包括两岸防洪堤总造价需32万元。由于工程量大,资金筹集困难,错过了施工季节,为确保三万亩农田灌溉,修复工程要求在入汛前后完成。倒虹吸系水下工程,加上施工期(4～5月)雨水多,排水困难,钢筋混凝土施工质量受到严重影响。完工后经放水试验,漏水量竞达到30%,倒虹吸下半部断 I. Overview Tongling County Xiao Ling Reservoir (medium) the main canal canyon ditch across the Creek in 1990 No. 15 strong typhoon was completely destroyed, as a direct impact on the downstream three thousand acres of farmland irrigation and Xiao Ling two or four Power generation plant efficiency, it is in urgent need of timely repair. After the on-site survey and analysis, it is unsafe and reliable to think that the original overcomer channel is located at the side of the spillway under the spillway. Therefore, it is decided to shift the inverted siphon scheme (section 2 × 2m, Q_set = 6.5m 3 / S). Project repair budget estimates, including the total cost of flood control banks across the Taiwan Strait need 320,000 yuan. Due to the large amount of construction and fund raising difficulties, the construction season was missed. To ensure the irrigation of 30,000 mu of farmland, the restoration project was completed before and after the flood season was completed. Inverted siphon underwater project, coupled with the construction period (April to May) and more rain, drainage difficulties, the quality of reinforced concrete construction has been seriously affected. After completion of the water test, the amount of water leakage to reach 30%, inverted siphon lower half off