Most people know nothing about the treatment of bridge frame deformation, but there are two commonly used methods: the prestressed method and the flame correction method.

Prestressed method. A tensioning device is installed under the main beam, and the main beam is arched through the tensile force of the reinforcing bars. In this way, the lower cover plate of the main beam generates compressive stress and the upper cover plate generates tensile stress, which is opposite to the stress caused by external loads. This offsets part of the working stress and thereby improves the stress state of the main beam. Therefore, the prestressed method has the purpose of reinforcing the main beam and correcting the deflection. This method is simple and easy to control. Its drawback is that it has limitations and complex bridge deformations are difficult to correct.

Powder-coated cable tray

Flame correction method for powder-coated cable trays. The flame correction method involves heating certain parts of the bridge frame. The heated parts expand, but they are restricted by the adjacent unheated parts and cannot expand freely. Therefore, the heated parts are compressed. After cooling, it shrinks again. During the cooling process of the heated part, it pulls the surrounding metals closer to each other, generating a contracting force, which is equivalent to applying an eccentric moment under the neutral layer of the main beam, causing the main beam to arch upward again and achieving the purpose of correcting structural deformation. The flame correction method is highly flexible and can correct various complex deformations of the bridge frame structure.