钢结构围护支撑体系顶管工作井施工工法

杨小山

摘要：传统顶管工作井施工，一般是在地面以上搭设施工平台制作钢筋砼沉井，待沉井养护完成后下沉，下沉完毕再进行砼封底，工序繁多，沉井预制养护下沉时间长。而本工程顶管工期仅有2个月，工期较紧;且工程位于杭州萧山国际机场内，顶管工作井位置距飞机跑道仅有10余米，故对施工高度有严格的限制;综上两点采用传统沉井施工方法，不能满足本工程施工要求。因此采用结构形式简单，易于控制施工高度的方法就显得尤为重要，根据本工程的实际经验，顶管工作井采用钢结构围护支撑体系，能有效解决工期紧、限高等问题，同时在顶管检查井施工完成后，钢结构可以回收再利用，大大节省了工程投资。为此，我们总结并编制了“钢结构围护支撑体系顶管工作井施工工法”。

Abstract： Traditional pipe jacking work well construction is generally to build a reinforced concrete sink well above the ground with a construction platform， after the sink well maintenance is completed， the sink is completed， and then the concrete is sealed back after completion of the sink. The process is numerous， and the precast maintenance sink time is long. The construction period of this project is only 2 months， and the construction period is tight; and the project is located in Hangzhou Xiaoshan International Airport， and the working position of the pipe jacking well is only more than 10 meters from the runway， so there are strict restrictions on the construction height， so the traditional sunk well construction method cannot meet the construction requirements of this project. Therefore， it is particularly important to adopt a method with a simple structural form and easy control of the construction height. According to the actual experience of this project， the steel pipe enclosure and support system adopts a steel structure enclosing and supporting system， which can effectively solve the problems of tight construction period and height limitation. After the construction of the inspection well is completed， the steel structure can be recycled and reused， which greatly saves the engineering investment. To this end， the "Construction Method of Jacking Working Well for Steel Structure Enclosure and Support System" have been summarized and compiled.

关键词：钢结构;顶管工作井;拉森钢板桩

Key words： steel structure;pipe jacking working well;Larsen steel sheet pile

中图分类号：U456.3                                   文献标识码：A                                  文章编号：1006-4311（2020）17-0126-03

1  工法特點

①本工法改变了传统工作井（沉井）：地上预制→养护→下沉→封底的工艺流程，采用钢结构围护支撑体系：钢板桩支护→钢支撑及围檩安装→封底的工艺流程，省去了沉井预制养护下沉的时间，大大缩短了施工工期。②本工法施工是在地面以下作业，解决了沉井地面预制超高问题，能满足飞行区不停航的施工要求。③钢结构支撑体系在顶管检查井施工完成后，可以回收再利用，大大节省了工程投资。

2  适用范围

本工法适用于：①工期特别紧张，采取常规沉井施工方法，无法保证施工工期要求的工程。……