Jishan No.2 Bridge of G324 line K28+475 has the original bridge deck width of 25m, but the junction road width is 33m, only the location of the bridge narrowed, affecting traffic safety. According to the first-phase plan of Fuzhou Highway Bureau in 2017, it was decided to widen the bridge by 5m on both sides so as to be consistent with the width of the junction road sections. The widened part on the left and right side is a non-motorized bridge. The superstructure is made of a 10m precast reinforced concrete simple-supported hollow slab girders, the substructure is made of light abutment and pile foundation. The left and right bridge abutments are only set up in the gutter side of the wingwall, which connected to the gutter retaining wall. The superstructure-bridge deck connection is not set up with expansion device, and the deck is extended by outsourcing type. Expansion joints are set up at the junction of the lap slab and roadbed behind the abutment.
The outsourced bridge panel extends to the back of the platform, consolidates with the back wall into a whole, covers the expansion joint at the abutment, and cancels the expansion device. In fact, it is to apply the "continuous bridge panel" method often used at the pier of the multi-span simply supported beam bridge to the abutment beam end, so as to cancel the bridge expansion device, in order to solve the problem of maintenance work and economic losses caused by the frequent damage of the expansion device. In addition, the structural form of the seamless bridge with the outsourced extension bridge panel wraps the support at the abutment to prevent the infiltration of external moisture, thus improving the durability of the support. By setting a certain length of unbonded layer between the main beam and the bridge panel close to the outsourced bridge panel, the beam rotation is allowed and transfer a small bending moment.
Since the operation of the bridge, the use effect is good, which can avoid the maintenance difficulties caused by the frequent damage of the bridge deck expansion device, greatly improve the traffic conditions, and produce significant social and economic benefits and social benefits.
The construction unit of the widening and reconstruction project of Jishan No.2 Bridge is Minhou Branch of Fuzhou Highway Bureau, the design unit is Fuzhou Luxin Highway Design Co. LTD, and the supervision unit is Fujian Luxin Traffic Construction Supervision Co., LTD. The College of Civil Engineering of Fuzhou University is responsible for the transverse research project with the bridge as the background. The design of the bridge has been guided and the structure of the bridge has been studied. The bridge was completed on Oct 9, 2017 and accepted on Dec 13, 2017.
(a) Bridge deck photos