The basic principle of bridge structural strengthening

Although there are many ways to strengthen the bridge and improve the bearing capacity of the bridge, the basic principles are all the same, and all of them follow the basic principle of mechanics. From the angle of external factors and internal conditions of bridge structure to strengthening for improving the bearing capacity.

From external factors, the bearing capacity of main girder can be improved by changing the performance of the structure.

1.Enlarging the section area of the main beam

The reinforcement methods include increasing the main reinforcement, shotcrete, cast-in-place concrete, increasing the section size of the wrapped concrete, and increasing the bridge deck to add auxiliary components.

The aim is to increase the inertia moment of the cross section of the main beam or the geometric flexural modulus. When the internal force of the load is unchanged or the load level is increased, the tensile force of the main beam section can be reduced by changing the coating of the section area, so that it can not exceed the bearing range of the material properties of the main beam, thus strengthening the main beam and improving the bearing capacity.

2.Increase the strength of the main beam

The main beam uses epoxy mortar to paste steel plates, carbon fiber fabric and other high strength materials to increase the strength of the main girder.

From the angle of underwear, we can adjust the internal force to increase the bearing capacity of the main girder.

To change the structure system of the original bridge, the simple supported beam system is changed into the connection beam system, the span of the bridge is changed with the eight character support, or the main beam structure is changed from the pure bending structure to the bending structure by the external prestress, so as to reduce the load internal force of the main girder, thus reducing the tensile stress of the main capacity of the bridge, improving the bearing capacity.