大直径圆形沉井不排水下沉施工技术研究

沉井施工是顶管施工的重要前置工程,以哈尔滨某管线工程为例,介绍沉井制作与沉井下沉2个施工的关键步骤,具体为沉井制作中的基坑开挖、基础处理、砌刃脚砖模和沉井壁制作,沉井下沉中的下沉准备工作、砂石垫层凿除、沉井下沉、管井降水和沉井封底。最后,对沉井下沉过程中的一些力学性能进行验算,主要有沉井下沉验算、沉井下沉稳定性验算、沉井封底验算,结果表明,验算结果均符合相关规范要求,能够保证施工的顺利进行。

Caisson construction is an important pre-engineering of pipe jacking construction.Taking a pipeline project in Harbin as an example,this paper introduces two key steps of caisson construction and caisson sinking,including excavation of foundation pit in caisson production,foundation treatment,brick molding of edge foot,preparation of sinking shaft,sand and stone cushion removal,caisson sinking,pipe shaft precipitation and bottom sealing of caisson.Finally,some mechanical properties in the process of caisson sinking are checked,including caisson sinking,caisson sinking stability and caisson bottom sealing.The results show that the checking results are in line with relevant specifications and can ensure the smooth progress of construction.