全防水复合衬砌隧洞结构设计

本文介绍了一种有压输水隧洞复合衬砌结构与高密度聚乙烯(HDPE)自粘胶膜防水卷材结合技术,即:采用自粘型防水卷材作为主要防水层,配以混凝土自防水的复合衬砌防水体系。该技术适用于具有防水要求的双层衬砌结构输水隧洞。采用这种双层衬砌防水技术,可以将防水层从以往的径向防渗增强为径向、轴向、环向防渗,解决了输水隧洞因为外衬或内衬局部渗水而导致衬砌间窜水的现象,增加了结构耐久性。这种结构便于运行期间进行检修、排查渗漏点。该技术已成功地在北京市南水北调配套工程东干渠工程中大规模应用。

Design of tunnel structure with full water proof composite lining

A technique of composite lining structure for pressure water conveyance tunnel combined with reeling material of HDPE（high density polyethylene）waterproof self-adhesive membrane is introduced herein， i.e. the waterproof self-adhesive membrane is taken as the main water-proof layer supplemented with a composite self-water proof lining system of concrete. This technique is suitable for the water conveyance tunnel of double-layered lining structure with water proof requirement. With this kind of double-layered water proof technique， the water proof layer can be reinforced from the previous radial anti-seepage into radial， axial axial and circumferential anti-seepages， and then the problem of the water channeling occurred in-between the linings caused by the local water seepages of the outer lining or the inner lining can be solved， thus the durability of the structure is to be enhanced as well. This structure is convenient for the maintenance and leakage inspection during operation. This technique is already successfully applied in large scale to the east main canal——ancillary works for the South-to-North Water Transfer Project in Beijing