Steel Cofferdam Construction Technology of the Main Pier Platform of Yongdingxinhe Super Major Bridge

During the construction of the main pier platform of Yongdingxinhe Super Major Bridge,the bottomless double-wall steel cofferdams are used for retaining soil and water.This paper introduces the design issues of steel cofferdams and the construction technology of making steel cofferdams into sections and blocks to processing,transporting and assembling them for sinking and pouring the bottom sealing concrete and the matters needing attention.After implementation,the design elevation,plane position and perpendicularity bias were controlled in an allowed bend to satisfy the construction requirements.