旋喷桩在顶管工程软弱土体加固中的应用

Application of Jet Grouting Pile to Strengthen the Weak Soil in Pipe-jacking Project

天津市南水北调中线滨海新区供水一期工程是天津市内输配水工程的重要组成部分,建设任务是向天津市滨海新区输送引江原水,输水管材采用2根直径2 600 mmPCCP管道,局部辅以钢管。输水管道所经紫阳道泥浆池占地面积大,泥浆较深,成为管道施工难点。根据现场地形、地质条件,经比较分析,采用顶管穿越方案,其中泥浆加固是方案的重难点。加固方案的选择不仅要安全可靠,还要经济,便于实施。经分析论证,采用旋喷桩加固方案,并确定加固范围、桩径、桩长、水泥掺量等重要参数。

The first phase of Binhai New Area Water Supply Project,Middle Route of South-North Water Transfer Project,is an important part ofthe city's water supply and distribution project.The task of the project is to transport raw waterfrom theriver to the Binhai New Area of Tianjin.The water delivery Two PCCP pipes with the diameter of 2600 mm were used for water transmission,supplemented partially by steel pipes.The slurry tank of Ziyang Road occupied a large area and had a relatively deep slurry,making it difficult for the pipeline construction.According to the site terrain and geological conditions,the pipe-jacking scheme was adopted by comparison and analysis of multiple schemes,in which mud reinforcement was the key and difficult point.The selection of reinforcement scheme should be not only safe and reliable,but also economical and easy to implement.After analysis and demonstration,the scheme of jet grouting pile was adopted.And the important parameters,such as reinforcement range,pile diameter,pile length and cement content,were determined.