At present, the reinforcement method of steel structure can be summarized as follows:

 

1) Increase the section method of the component (such as the sticking steel method);

 

2) Improve the structural stress system (such as adding beams and columns, etc.);

 

3) Prestressing technology reinforcement method.

 

The commonly used methods for strengthening the section are: increasing the section height, thickening the flange plate, and changing the section into a box section. The main reinforcement method for increasing the cross section of the steel structure is bonded steel or carbon fiber cloth. These two methods have relatively small damage to the structure itself, and in recent years, the domestic development is relatively fast, and the application is gradually increasing. However, the application of steel structure reinforcement is relatively small, especially in the normal use condition. problem. Moreover, the construction of bonded steel or carbon fiber is relatively difficult, and the surface of the original structure must be treated, smoothed, and smoothed before being pasted. Debonding may occur when the structure is subjected to dynamic loads or high temperatures.

 

Adding reinforcement methods such as beams and columns to improve the structural stress system can effectively and significantly reduce the load effect of the structure, so that the bearing capacity of the structure meets the requirements, and the investment of this method is not high, and the economic benefit is very good. This method is very feasible when the building structure does not have any special requirements, but it is not suitable for structures requiring large spaces.

 

The external prestressing technology reinforcement method refers to arranging the prestressing tendons outside the section of the structural member to be reinforced, reducing the load effect of the component by changing the force transmission path of the structure, and improving the bearing capacity of the structure on the original basis of the structure. Improving the deformation performance of the structure and reducing the stress in the rod can restore the damaged engineering structure to its original technical function, thereby meeting the requirements of the new bearing condition and function. The structure consists of prestressed tendons, pipes, anti-corrosion materials, steering blocks, anchoring systems and other components.

 

Although the method of external prestressing steel beam reinforcement has the advantages of operability, economy and safety, at this stage, there are few research experiences and engineering practices in this area, and its obvious economic and social benefits need further study.