ABSTRACT
Chekiang Road Bridge is a riveted steel truss bridge over one century cross Suzhou River in Shanghai. The bridge was designed by the British and built in 1908. Now it is an immovable cultural relic of Shanghai. Although many times of maintenance and reinforcement have been carried out, there are still some locations can’t be achieved by conventional repair method and the results are not satisfying, and the safety of the structure can’t be ensured. Therefore the bridge needs to be moved ashore to repair thoroughly.
The bridge is across Suzhou River with one span of 59.75 m, and the total width of the original bridge was 14.352 m. A one-way motor lane was arranged between the main trusses with clear distance of 6.8 m. Outside the main truss, there were a 2.16 m nonmotorized lane and a 1.08 m sidewalk which were widened during previous repair. Main girder with fish shape was a simply supported steel truss. Bridge deck consisted of longitudinal and transverse steel beams, cast-in-situ concrete plate, and asphalt concrete pavement.
According to the careful detection in the repair, steel fatigue is not serious, and structural damage is mainly corrosion of steel members. Because of improper structure details, some steel members are too seriously corroded to keep on using safely. They are mainly below the deck.
For implementing an overall rehabilitation, the bridge was moved ashore as a whole to carry out the rehabilitation procedure. In order to increase the traffic capacity, the clear distance of the main trusses was enhanced from 6.8 m to 8.5 m to contain a single lane motorway and two bicycle ways. The original concrete deck was replaced by a new orthotropic steel deck. In order to preserve the cultural information, the majority of the steel components of the main trusses were retained. Some severely corroded components were replaced by new steel for structural requirements. The top lateral bracings were replaced and designed in their original style to restore historical features. The connection between old steel components, or new steel and old steel components still employed rivets. For the connection between new steel, riveted joint should be applied above the deck to obtain “old” appearance and welded joint could be applied under the deck.
The bridge was shifted to the north bank of the river using a buoyant tank, a 600 ton crawler crane and SPMTs. A temporary steel workshop was built to implement steel structure construction. When steel structure construction in the workshop was completed, the bridge was shifted to its original position with the reverted procedure as it was shifted to the bank.
During maintenance process, the structural form and structural details of the original design was retained as far as possible. Considering better anticorrosion, steel orthotropic deck was used, and the waterproof and detail structure were improved to enhance the durability. According to traffic demand and capacity of the structure, truss spacing was appropriately widened to enhance traffic function.
After rehabilitation Chekiang Road Bridge has been successfully moved back to the original position.
