Design of an Arch and Girder Coordination System Bridge

The main span of the Dengjiayao Bridge is 158 m long.The bridge was designed as a coordination system of half-through arch bridge and simply-supported girder bridge supported by triangular frames for the purpose of enhancing the spanning capacity of the structure.Through comparison of the different proposed design of the bridge,it was determined that the arch ribs would be used with the steel and concrete hybrid structure,namely the sections of the structure close to the arch springs at both sides were of concrete boxes while the sections of the structure at midspan were of steel boxes.The horizontal thrust at the springs was jointly carried by the tie members and group pile foundations,for which a combination system having 3 rows of piles in a foundation transverse to the bridge and 4 rows of the piles along the bridge plus 15 000 kN tie member force were chosen after optimal design.The floor system was the grid type steel and concrete composite girder that can reduce the weight of the superstructure and facilitate the construction.The construction of the bridge within 10-month time proved both the landscape effect and economic benefit of the completed bridge were good.