For bridges whose load-bearing performance does not meet the requirements, there are two ways to deal with them: one is to demolish and rebuild; the other is to take appropriate reinforcement measures to restore and improve the bridge's load-bearing capacity to meet the current transportation needs.

The reinforcement and reconstruction of the old bridge is more economical than the demolition and reconstruction. It can not only save a lot of resources, but also produce good economic, social and environmental benefits. It is feasible to restore and improve the carrying capacity and traffic capacity of the dangerous bridge, and to extend the service life of the bridge to meet the needs of modern transportation. And it is of positive significance for maintaining the normal operation of road traffic and ensuring the economic development of the areas along the route.

The commonly used reinforcement methods for concrete beam bridges include sticking steel plate method, sticking fiber cloth method, prestressing method, simply supported variable continuous method, and increasing section method, etc.

Compare and analyze the reinforcement effect of commonly used reinforcement methods

1) When using the bonded fiber cloth method to reinforce the upper member of the bridge, the rigidity of the structure is not greatly improved, so it is not suitable for the use of functional reinforcement that mainly controls structural deformation. And under normal conditions, the effective use period is generally 7 to 8 years.

2) The pasted steel plate has a certain restrictive effect on the further development of structural cracks, but it does not make much contribution to improving the durability of the structure. Therefore, the steel plate reinforcement method is not suitable for use in high humidity and medium corrosive environments, and the effective use period is generally 7 to 8 years under normal conditions.

3) Adopting the method of increasing section to reinforce the flexural member, which increases the effective height of the beam, can significantly increase the bending stiffness of the beam, and is also beneficial to solving the problem of live load deformation or excessive vibration.

Establish a post-appraisal method for bridge reinforcement and reconstruction technology in order to evaluate the reinforcement effect more reasonably and effectively, provide a reference for the selection of bridge reinforcement and reconstruction engineering methods, and reduce the cost of bridge reinforcement and repair. Provide the bridge management department with a basis for evaluation after bridge reinforcement and save maintenance funds.