裸岩区深水基础先堰后桩建造技术研究

Study on Construction Technology of Weir First and Pile Later for Deep Water Foundation in Bare Rock Area

以清溪口渠江特大桥5号主塔桥墩深水基础为背景,研究一种满足裸岩区先堰后桩的建造技术,包括大型钢围堰气囊下水、浮运、定位、下沉和钻孔平台搭设与钻孔等关键工序。运用有限元软件对双壁钢围堰在各不利工况下的受力性能进行分析,结果表明:双壁钢围堰的整体强度、刚度和稳定性均满足施工要求;钢围堰封底混凝土的厚度以及围堰的浮游稳定性也满足施工要求。

Based on the deep-water foundation of the main tower pier of Qingxikou Qujiang bridge,a construction technology of weir first and pile later in bare rock area is studied,including key processes of large steel cofferdam launching,floating,positioning,sinking,drilling platform erection and drilling.The finite element software is used to analyze the mechanical performance of double wall steel cofferdam under various unfavorable working conditions.The results show that the overall strength,stiffness and stability of the double wall steel cofferdam meet the construction requirements.The thickness of the bottom concrete of the steel cofferdam and the floating stability of the cofferdam can also meet the construction requirements.