小导管注浆技术在南水北调暗涵工程中的应用

南水北调中线北京段西四环暗涵为砂砾(卵)石地层,采取浅埋暗挖法施工。其中,小导管超前注浆至关重要,它不仅是控制施工进度的主要因素,还是保证施工安全的有效方法,既能起到超前勘探和超前锚杆的作用,又能加固土体,防止掌子面坍塌。为此,对南水北调中线北京段西四环暗涵浅埋暗挖施工中小导管注浆技术进行总结,以为今后类似工程提供参考和借鉴。

The Application of Grouting by Mini Pipes in the Covered Culverts of the South-North Water Transfer Project

The rock formation of the foundation of the covered culverts at the west No.4 ring road in Beijing section of the Middle Alignment of the South-North Water Transfer Project was sand and gravel.The shallow covered underground excavation method was adopted.Therefore the pilot mini-pipe grouting would play a very important role in keeping up with the construction schedule and safety requirements.It could offer not only pilot investigation and pilot anchorage,but also consolidation of earth materials and prevention against collapse in the heading.This paper sums up the technology of the mini-pipe grouting used in the covered culverts at the west No.4 ring road in Beijing section of the Middle Alignment of the South-North Water Transfer Project.