TRIAL DESIGN STUDY ON ULTRA-HIGH PERFORMANCE CONCRETE COMPOSITE PIER OF BAY BRIDGE

The construction method of bridge piers is usually cast in place with steel formwork It is time-consuming due to affected by the storm and formwork assembling or disassembling, the construction progress is slow. A large number of steel formwork and marine concrete lead to high cost of bay bridge. Even to the extent that the corrosion resistance and impermeability are not ideal. Ultra-high performance concrete (UHPC) not only has high strength, but also has good resistance corrosion resistance and impermeability. It can replace the existing steel formwork. Based on the actual engineering of Pingtan strait bridge, use the precast thin cylinder of UHPC as the formwork then pour ordinary concrete into it to form the UHPC-RC composite pier. Through the comparison of the steel formwork and UHPC formworkformwork in the cost of construction, mechanical properties and durability, it can be found that the trial design pier has higher bearing capacity, better durability of the structure andlower cost which saves nearly 30% compared to the original design. The research can provide reference for the design of bay bridge in the future.