Bridge reinforcement generally refers to the restoration and enhancement of the carrying capacity of an existing bridge through the reinforcement of components and the improvement of structural performance, in order to extend its service life and meet the requirements of modern transportation.

1) Strengthen the weak components

For weak members with serious defects on the bridge or failing to meet the safety load requirements due to passing heavy vehicles, it is common to increase the cross-section of the main girder or main arch with new material (shotcrete, concrete, steel plate,carbon fiber reinfroced polymer, plant rebar ), and use of high-grade cement mortar or epoxy cement mortar filling cracks, adding external post-tensioning tendons, the application of external prestress, or the use of chemical adhesives affixed to the additional method of reinforcement.

2) Add auxiliary components

When the bearing capacity of the bridge is not sufficient or the bridge is damaged due to various reasons, new structural members may be added to the original structure, such as the addition of stringers, beams or arch ribs. Alternatively, the new structure may be replaced with new prefabricated structures,there are serious defects in the surface and not easy to repair components. When replacing components, sufficient temporary support must be provided and reliable technical measures must be taken to ensure the safety of the entire structure during construction.

3) Change the structural system

Change the structural system is to use the continuous beam, beam-slab combination and the combination of the role of arch and beam structure to change the force system, to improve the structure of the stress conditions in order to improve the ability of the bridge to withstand live load. Such as the simple beam into a continuous beam, the hinge changed to just access, the use of auxiliary piers, bracing, etc, will be multi-span single span structure, and in the arch bridge deck cast a layer of reinforced concrete panels, the arch system convert to beam system.

4) Reduce the dead load

Relieving the ballast constructed on the upper part of the original bridge can improve the stress condition of the original bridge and enhance the ability to withstand live load. Especially when the bearing capacity of the bridge foundation is limited and can not meet the requirements of strengthening and increasing the bearing capacity requirements of live load, it is a cost-effective measure to reduce the load carrying capacity of the bridge by reducing the deadweight of the bridge. 

5) Reinforcement pier and foundation

A considerable part of the bridge defects and diseases caused by pier or foundation problems. The bridge is usually taken to use reinforced concrete hoop, the use of reinforced concrete tie rods and steel bars to impose additional prestress, increase pile and push the bridge and other measures to strengthen the pier and abutment to improve the abutment and the foundation of the force , improve the carrying capacity of the bridge