When steel structures are damaged, the problem must be found and solved immediately. The main causes of steel structure damage are as follows:

1) Load changes, overdue implementation, changes in standards and regulations structure bearing capacity is insufficient

2) Parts are deformed, twisted, obstructed and depressed due to various accidents, parts section becomes weak, parts warpage, connection rupture and so on

3) Temperature difference effect causes component or connection deformation, crack and warpage

4) Due to chemical corrosion and electrochemical corrosion, the cross-section of steel structure components is weakened

5) Others include mistakes in planning, production, construction and illegal use and operation during implementation.

There are three main technical measures for steel structure engineering reinforcement:

1) section strengthening method: part or along the whole length of the parts with steel strengthening, connecting the overall common force

2) Change the simple calculation diagram: add additional support, adjust the load distribution, reduce the level of internal force, force the statically indeterminate structure support displacement, reduce the stress peak

3) Prestressed cable method: the use of high strength cable to strengthen the weak link of the structure, improve the overall bearing capacity, rigidity and stability of the structure.