Research Of The Key Technology In The Foundation Structure Of The Non-Open Part Of Donghai Bridge

Donghai Bridge is literally the first over-the-sea bridge ever built offshore in China, the total length of which is 31.5 km and width is 36.5m. Fewer experiences are available in engineering and constructing such bridge in China by now. The natural conditions of the bridge location are complicated and severe, especially the hydrogeological conditions are unsuitable for construction. So it is necessary to take a systematic study in the key technology of the foundation design of Donghai Bridge.Because 92 percent of the bridge is non-open to navigation, the reasonable foundation structure of the non-open part is the key factor related the safety, quality, cost and construction period. In this paper, the key technology hase been deeply analyzed based on several parts as pile foundation type, shape of pier, pier construction, water scouring and wave-current test. Large amount of big diameter steel pipe piles are adopted in engineering as the first time in China, and the piles are made of longer subsections than ever and driven in total, which leads to a faster construction. In the process of design, ocean dynamics theory is used systematically in over-the-sea bridge engineering for the first time. In domestic field of the over-the-sea bridge engineering, it is the first time to adopt large numbers of concrete jackets by hoisting in whole in solving the problem of pier construction offshore. And the technology of hoisting the whole big tonnage precast pier and connecting the piers by casting in site are advanced in domestic bridge engineering and successful in this project. Because of the advanced technology, a mass of work should be taken offshore are finished onshore, which greatly reduces the risks during the construction process, shortens the construction period. The advanced technology is a solid foundation to ensure that the Donghai Bridge is open to traffic on time.