复杂环境中高地下水位区深基坑倒挂井壁逆作法技术

Upside-down hanging side wall reverse construction method of deep foundation pit in high groundwater level area in complex environment

深埋既有管线碰接改造一直以来是繁华城市街区内管线迁改工程设计与施工的重难点,以深圳市轨道交通9号线二期工程为例,介绍了复杂环境中高地下水位区深基坑倒挂井壁法技术在该工程管迁迁改中的应用。为地铁车站附属工程提供施工条件并确保城市供水管网正常运营,拟对附属影响范围内既有深埋管线进行改迁,迁至车站主体结构顶板上方,在管线碰接改造深基坑开挖范围内原管线需要保护性开挖,导致管线宽度范围围护桩无法施工。为了解决深基坑管道安全区域范围围护桩无法施工的难题,采用倒挂井壁逆作法+旋喷桩止水+袖阀管注浆止水,成功解决上述难题,为同类工程提供参考。

Taking the second phase project of Shenzhen Metro Line 9 as an example,this paper introduces the application of deep foundation pit upside down well wall method in the complex environment.In order to provide construction conditions for the auxiliary works of subway stations and ensure the normal operation of the urban water supply network,it is proposed to change the existing deep buried pipelines within the auxiliary influence area and move them to the top plate of the main structure of the station.In the excavation range of deep foundation pit for pipeline collision transformation,the original pipelines need to be protected by excavation,resulting in the construction of retaining piles within the width range of pipelines.In order to solve the problem that the retaining pile can not be constructed in the safe area of deep foundation pit pipeline,upside-down hanging side wall reverse construction method+rotary jet pile+sleeve valve pipe grouting is adopted to successfully solve the above problems and provide reference for similar projects.