1) Increasing member section (such as the steel bonding method);

 

　　2) Improving the structural force system (such as adding beams and columns);

 

　　3) Prestressed technology reinforcement method.

 

　　Common methods for increasing the section include: increasing the section height, thickening the flange plate, changing the section shape to a box section, etc. The main reinforcement methods for increasing the steel structure section are steel bonding or carbon fiber cloth pasting. These two methods cause relatively little damage to the structure itself, and have developed rapidly in China in recent years, with increasing applications. However, their application in steel structure buildings is relatively limited, especially regarding their service life under normal use. In addition, the construction of steel bonding or carbon fiber is relatively difficult, requiring the original structural surface to be treated, ground, and smoothed before bonding. De-bonding may occur when the structure is subjected to dynamic loads or high temperatures.

 

　　Adding beams and columns to improve the structural force system can effectively and significantly reduce the load effect of the structure, thus ensuring that the load-bearing capacity of the structure meets the requirements. This method has low investment and excellent economic benefits. When the building structure has no special requirements, this method is highly feasible, but it is not suitable for structures that require large spaces.

 

　　The external prestressed reinforcement method refers to placing prestressed tendons outside the section of the structure to be reinforced. By changing the force transmission path of the structure, the load effect of the member is reduced, and the load-bearing capacity of the structure is improved based on the original structure. This method improves the deformation performance of the structure, reduces stress in the members, and can restore the damaged engineering structure to its original technical functions, thus meeting the requirements of new load-bearing conditions and use functions. The structure consists of components such as prestressed tendons, pipes, anti-corrosion materials, turning blocks, and anchoring systems.

 

　　Although the external prestressed reinforcement method for steel beams has advantages in terms of operability, economy, and safety, there is currently limited research experience and engineering practice in this area, and its significant economic and social benefits require further research.