The Nianzigou bridge is located in National Road G244, Shaanxi Province. The bridge span and width are 13m and 12.5m, repectively. The superstructure is prestressed concrete hollow slab structure. The bridge deck pavement is composed with 9cm asphalt concrete, ATR-1 type waterproof layer and 10cm C40 concrete. Rigid anti-collision railings are set on both sides of the bridge, and grade flat approach slab of 5m long are set at both ends of the bridge. This bridge is a semi-integral abutment bridge, the end beams on the abutment are rigidly connected to the girders, and the lower part of the abutment is connected to the superstructure through bearings, thus eliminating the expansion joints and deck expansion devices at the abutment, avoiding the maintenance and repair of the deck expansion devices, and improving the usability and durability of the bridge. At the same time, because the main girders are connected to the abutments through the bearings, neither bending moment nor shear force is transferred, making the additional forces on the bridge caused by temperature changes, concrete shrinkage creep and pier settlement differences smaller compared to the overall bridge. Drainage pipes are installed in the lower part of the end girders to facilitate drainage, and foam filler is installed between the end girders and the ear walls to accommodate the deformation of the main girders and to prevent water from eroding the main girders.
The Nianzigou bridge was constructed by Baoji Highway Administration and designed by Xi'an Highway Research Institute. The School of Civil Engineering of Fuzhou University is responsible for the scientific research project with the bridge as the background, and has guided the design of the bridge and carried out research on the bridge structure. The bridge was completed and opened to traffic in June 2020.
(a) Side view of the bridge
(b) Pavement