Study On Construction Technology Of The Deep Underwater Pile Foundation Of Wulongjiang Bridge (The New Double Line Bridge)

The construction technique level of bridge Deep pile foundation engineering is the key to guarantee the completed time of entire place bridge,and its quality of constructing.The project of Wulongjiang bridge (the New Double Track Bridge )in Fuzhou,which is difficult to construct,has many different remarkable specificities to other bridge deep water foundation,such as the pile foundation occupying in the deep water,the complex of construction environment and hydro geological condition.The article,developed the deep pile foundation construction engineering technology against this project,proposed a practical and reasonable plan of construction,which has very realistic project significance that guaranteed the security and quality of construction,and realized the management goals of anticipated finishing time,cost,and so on.This paper aims at the key issues about Wulongjiang Bridge(new double track bridge) during the foundation construction of deep-water pile,including the structure plan of the construction platform,the force-bearing analysis and structure design of the construction platform,the build of the construction platform and construction technology and quality control measures of The bore-hole cast-in-situ pile ,carry out a more in-depth systematic study.The main works are as follows:First,thoroughly and systematically analysed the area topography,lithology,gelolgical structure,hydrogeology and constructure environment of Wulongjiang Bridge,clear the specificity and constraint of this project.Second,compare and analyse the steel cofferdam platforms,the floating platforms,the steel tube pile platform and the steel pipe pile platform from the view of technology and economy,demonstrate the feasibility of the combination of the steel tube pile platform and the steel pipe pile platform.Third,optimize this project by combining the specificity and constraint of this project,then put forward the"the guide pile +Bailey truss girder the bridge pile top and bridge panels anchor system"platform strcture optimization scheme.analyse and calculate the load on the platform,then design the whole structure and construction drawing of the platform structure,and use the Midas/Civil finite element software to analyse interner force and displacement,which is under the two conditions of single pile cantilever and three rigs work together,arrive at a conclusion that the structured of the construction platform is reasonable,the work traits is good,the construction safe can be sure.Fourth,for the key links in construction technics,including construction platform construction,steel pipe pile construction and bored pile construction,etc.Abstract the pertinence construction key points or cautions,and put forward measures for quality control.After finishing the erection of construction platform and the observation of displacement and settlement at crime scene, the result tallied with the result of finite element analysis and well met the intended purpose and effect that proved the rationality of the construction platform. The construction has been guided in accordance with the quality control measure. And some parts of projects under construction have been made for I bored pouring piles with the continuous and flawless body. Both the gradient and axis offset of the piles were 100% controlled inside the allowable value of specification. And the concrete of pile bodies were 100% qualified. It was showed that the proposed technical measures of construction for the bored pouring pile in the deep water were effective in this project.The results of research obtained good stage technique and economic benefits,it also has certain reference value for the future of Deep pile foundation construction of similar bridges.