裸岩地质双壁钢围堰施工技术

Construction Technology of Double Wall Steel Cofferdam in Bare Rock

新井冈山大桥的钢围堰在拼装平台上分节拼装,并根据施工水位确定采用2节或3节整体下放。下放时在围堰壁板内对称平稳注水,各钢箱侧面板充当注水隔板,钢围堰制作位于桥位西岸的钢结构加工场,制作完成后采用分节运输至现场安装,分层整体拼装完成后,采用6台200t液压千斤顶整体同步进行下放,钢围堰下放到预定的河床位置后,采用3种方法进行堵漏围堰,并及时清理河床,完成封底混凝土浇筑,最终成功完成封底抽水。

The steel cofferdam of new Jinggangshan bridge shall be assembled in sections on the assembling platform,and2 sections or 3 sections shall be integrally lowered according to the construction water level. During lowering,water is injected symmetrically and stably in the cofferdam wall plate,each steel box side panel serves as a water injection clapboard,the steel cofferdam is manufactured in a steel structure processing field on the west bank of the bridge site,and is transported to the site for installation by sections after the production is completed; after the layered integral assembly is completed,six 200 t hydraulic jacks are adopted for overall synchronous lowering; after the steel cofferdam is lowered to a predetermined riverbed position,three methods are adopted for leakage stoppage cofferdam,and the riverbed is cleaned in time,the back sealing concrete pouring is completed,and the back sealing pumping is finally completed successfully.