Steel structure is often used in a wide range of engineering structures with large span, high height, large load and large dynamic action. With the development of steel structure, its stability is more and more important. Today, I will tell you about the five reinforcement methods of steel structure construction.

One, change the steel structure calculation figure reinforcement method

The structure is strengthened by changing the load distribution, the way of force transmission, the nature of joints and the boundary conditions, adding additional bars and supports, applying prestress, and considering the coordinated work of space. The general method to change the structure to calculate the graph is as follows:

(1) add supports to form a spatial structure and check the calculation according to the spatial structure. Add supports to increase the structural stiffness or adjust the natural vibration frequency of the structure, so as to improve the bearing capacity of the structure and the dynamic characteristics of the structure;

(2) support or auxiliary bars are added to reduce the slenderness ratio of the structure to improve its stability;

(3) in the bent frame structure, the stiffness of a column should be strengthened to bear most of the horizontal force, so as to reduce the load of other columns.

Second, additional fulcrum reinforcement method

After adding fulcrum in the middle of the span, the span of beam and plate is reduced, which can greatly improve the bearing capacity and reduce and limit the deflection of beam and plate. It is suitable for the reinforcement of beam, plate, truss, net and other horizontal structures in the long span structure with unrestricted clearance. Its advantage is simple and reliable, the disadvantage is that the use of space will be affected.

Three, paste fiber reinforced plastic reinforcement method

Pasting fiber-reinforced plastic reinforcement method in addition to the similar advantages of bonding outside the steel reinforcement method, also has corrosion resistance, moisture resistance, almost no increase in structural weight, durability, maintenance costs lower advantages, but need special fire treatment, suitable for all kinds of mechanical properties of concrete structural members and general structures.

After reinforcing project is finished, apply small hammer to knock to stick steel plate gently, judge bonding effect from sound or detect sticking density with ultrasonic method. If the anchoring area paste area is less than 90% and the non-anchoring area paste area is less than 70%, then the paste is invalid and should be peeled off and pasted again.

To major project, in order to inspect consolidate effect, must sampling undertakes load test, make standard use load test only commonly, the load that is about to unload goes adds completely afresh, the deformation of its structure and crack develop should satisfy design to use a requirement.

Fourth, has the bonding outside the steel reinforcement method

Generally, the reinforced concrete beam reinforced with steel coating is strengthened by wet outsourcing method, that is, epoxy resin grouting and other methods are adopted to bond the section steel and the reinforced member into an integral whole. As the section area of the steel under tension and compression increases greatly, the bearing capacity and section stiffness of the normal section also increases greatly.

Technology of reinforcing steel structure by prestressing

The bolt connection needs to cut holes in the base material near the damaged part to weaken the section and form a new stress concentration area. Ordinary bolts are easy to loosen under the action of dynamic load, and the stress relaxation of high-strength bolts is easy to occur, which reduces the repair effect of the structure. The technology of steel bonding and strengthening is to use special building structure glue to stick steel plate on the surface of steel structure, and rely on the structural glue to make it bond into the whole work together, so as to improve the bearing capacity of the structure. The disadvantage is that the structural weight increases a lot, the steel plate is not easy to make into a variety of complex shapes, transportation and installation is also inconvenient, and the steel plate is easy to rust, affect the bonding strength, high maintenance costs.