明沟结合管井降水方案在南水北调工程中的研究与应用

南水北调中线瀑河渠道倒虹吸工程地处地质构造复杂、节理裂隙发育、地下水极为丰富地带，排降水成为影响工程进度的一个主要难题，从多种排水和降水方案中，经多次论证，确定基坑内设明沟排水，加快抽水速度，保证排水量，以提高开挖进度。基坑两侧设管井排水，以保证基坑边坡稳定组合的方法，也就是明沟排水结合管井降水方案，这样既满足了工期要求，又满足了边坡稳定的需要，从而实现了本工程深埋段干场施工作业和边坡稳定。

Study and Application of the Precipitation Plan by Combining Open Channel with Tube Well in the South-to-North Water Transfer Project

The inverted siphon project of the Bohe River canal in the South-to-North Water Transfer Project located in the area with a complicated geological structure, rich joint growth and ground water. Draining and precipitating water becomes main problems influencing the project schedule. After many times argumentation and schemes choosing, we decided to pave an open channel to draining water in the footing groove to accelerate the pump speed and ensure the displacement for increasing the excavating tempo. Setting up tube well to drain water on both sides of the footing groove is a way to combine border and slope steadily, i.e. the precipitation plan by combining open channel with tube well, which can satisfy both the requirement of project schedule and stability of border and slope to achieve the dry-site construction in deep-buried section of this project and the stability of border and slope.