The earthquake caused immeasurable losses to people's lives and property. Summing up past experience, the most threatened people in the earthquake are collapsed buildings. With the continuous improvement of people's anti-seismic awareness, people have increasingly higher requirements on the anti-seismic performance of buildings.

The tragedy caused by the earthquake tells us that the collapsed buildings are often caused by the performance degradation due to the failure of the seismic performance or the long service time of the building. The decrease in strength and durability of analog buildings can be compensated by structural reinforcement. Is it possible to improve the seismic performance of the structure through special seismic reinforcement?

Seismic reinforcement analysis

In fact, the reinforcement and reconstruction can indeed improve the seismic performance of the structure.

However, the structural seismic reinforcement is not the same as the conventional structural reinforcement.

To enhance the seismic resistance of a structure, it is first necessary that the structure can effectively resist the side load during an earthquake, and at the same time, it must have a certain deformability under the premise of ensuring integrity to alleviate the severe energy transmitted by the earthquake. This is quite different from conventional reinforcement.

For different building structures, there are also different trends in seismic reinforcement.

The deformability of the masonry structure is insufficient and the integrity of the house is poor. When an earthquake occurs, large-scale collapse and severe damage are prone to occur under the action of reciprocating loads. Therefore, in seismic strengthening, we must focus on improving the deformability and integrity of the masonry structure.

The concrete structure opposite to the masonry structure will also produce larger deformation and more severe damage during earthquakes. In terms of integrity, the concrete structure is superior to the masonry structure. The poor seismic performance of the concrete structure is mainly reflected in the insufficient lateral bearing capacity and deformation capacity of the concrete structure. Therefore, in the seismic strengthening of concrete structures, the focus is on improving the seismic bearing capacity and overall deformation capacity.

Common methods of seismic reinforcement

Due to the different defects and different reinforcement points of masonry structures and concrete structures in earthquakes, and the consideration of different substrates, the two also have different reinforcement methods.

For the seismic strengthening of the masonry structure, the reinforcement method of the reinforced concrete surface layer or the reinforcement method of the reinforced concrete surface layer can be used to improve the lateral bearing capacity of the masonry structure. It is also possible to increase the structural integrity by adding additional ring-beam structural column reinforcement methods to improve seismic performance.

In the earthquake-resistant reinforcement of concrete structures, the commonly used carbon fiber structural reinforcement or stick steel reinforcement can still be used.

Carbon fiber cloth reinforcement and bonded steel reinforcement can effectively enhance the seismic performance of the structure from the perspective of improving the bearing capacity of the structure. However, when using these two methods, it is necessary to pay attention to the principle of seismic reinforcement. In the earthquake-resistant reinforcement of concrete structures, it is necessary to start from improving the overall earthquake resistance of the house to prevent uneven distribution of the rigidity and bearing capacity of the entire structure due to improper reinforcement, and the formation of new weak links. Carbon fiber or bonded steel is used for reinforcement. If necessary, other methods must be supplemented to improve the deformability of the concrete structure, and the safety of the structure is guaranteed from the dual perspectives of deformability and bearing capacity.