高地下水位渠道工程施工排水方案探讨

Discussion on Drainage Scheme of Canal Construction in High Water Level

对于大型渠道工程而言,由于其挖深一般较大,在穿越高地下水位地区时,渠道开挖、换填和衬砌施工就必须妥善处理地下水问题。南水北调中线一期工程总干渠全长1 431.95 km,沿途经过河南、河北、天津和北京四省市。该工程以明渠自流方式为主,按“宜渠则渠,宜管则管,宜涵则涵”的原则,采取局部渠段管涵输水方式。由于河南境内地势起伏较大,最大渠道挖深超过40 m。南阳段位于渠道前端,部分渠段地下水位最高处距原始地面仅有1.50 m左右,且地下水十分丰富,对工程施工造成较大影响。为了有效解决施工排水问题,施工单位河南省水利第二工程局做了大量的试验研究工作,最终确定采用“以明排为主,管井降水为辅”降排水方式,取得了一定效果。文章通过具体案例分析探讨地质条件复杂的大型渠道施工排水方案,为类似工程提供借鉴。

For large canal projects,due to their deep excavation,proper handling of groundwater issues is necessary during the construction of cutting,backfilling,and lining,especially when passing through high groundwater areas.The main canal of the first phase of the Middle route of the South-to-North Water Diversion Project is 1431.95 km long,passing through Henan,Hebei,Tianjin and Beijing.The project mainly uses open channels for self-flow,and adopts partial channel culverts in accordance with the principle of"appropriate channels for drainage,appropriate pipes for drainage and appropriate culverts for drainage".Due to the large relief in Henan Province,the largest channel depth is more than 4O m.Nanyang Section is located at the front of the channel,and the highest groundwater level of some sections is only about 1.50 m away from the original surface.Groundwater is very abundant,and has a great impact on the construction of the project.In order to effectively solve the problem of construction drainage,the construction unit of Henan Provincial Water Conservancy Second Engineering Bureau has done a lot of experimental research work,and finally determined the use of"open drainage as the main,pipe well precipitation as a supplement"drainage method,achieving a certain effect.This paper discusses the drainage scheme of large channel construction with complex geological conditions through case analysis,which can provide reference for similar projects.