The Application Of Pile-membrane Cofferdam On Bei Yunhe Synthesized Alteration Engineering

As a hydraulic engineering, the synthesized alteration of urban watercourse, withits complicated process and the broad range of influence, may effect the surroundingenvironment and the water quality, especially during the construction. Constructioncofferdam is a temporary water-retaining structure used to protect the constructionground of the hydraulic structure. The quality of cofferdam building material, itsimpermeability and stability will influence environment and other aspects directly,including the quality of the project, safety of the project, progress and investment ofthe project.In this paper, the author analyzed the characteristics and the deficiency betweenclassical cofferdam and pile-membrane compound cofferdam, compared thedifference of them, finally chose the pile-membrane compound cofferdam astemporary water-retaining structure. The pile-membrane compound cofferdam havemany merits, including less quantities, ease of construction, less pollution to waterquality, less investment and ease of demolishing, though the construction experienceof it is not sufficient.Using theoretical calculation and FEM software calculation, different workconditions of the cofferdam are numerically analyzed, including the stability of thepiles, infiltration flow, strength of the membrane and so on. The result of thetheoretical calculation shows that the pile-membrane compound cofferdam can beapplied into practical engineering as a safe construction cofferdam.Combining the Bei Yunhe synthesized alteration engineering, the author studiesthe main construction methods and how to found a practically feasible assurancesystem of quality and safety. Finally the corresponding construction method isestablished to assure the successful implement of the engineering.The application of the pile-membrane compound cofferdam in practicalengineering is successfully achieved. The fact also shows that the expected socialbenefit and economical benefit. The successful application in the Bei Yunhesynthesized alteration engineering and the other engineering approves that thiscofferdam type has great utility value in alteration of urban watercourse. The authorsummarizes the experiences and lessons in construction, analyzes the correspondingissue existing in construction, and finally brings forward some rational suggestion onconstruction process.