Seismic enhancement of steel structures is one of the methods used to strengthen steel structures against earthquakes. They use seismic optimization of steel structures to reach the desired performance level of the structure, which must be done in accordance with building evaluation and improvement rules.
Seismic improvements are made to steel structures to increase the integrity of the structure during an earthquake, and improvement and strengthening are done when buildings and structures are damaged due to earthquakes and other factors.
The difference between strengthening and seismic improvement of steel structures
In strengthening, the capacity of the structure is increased so that it can equal its seismic demand, but in optimization, the goal is to be able to equate the capacity of the structure with the seismic demand of the structure.
In strengthening, this is done by adding shear wall clamps and other things, or even by increasing the strength of the structure, such as: adding steel concrete jacket form, etc.
In some structures, it is possible to reduce the seismic demand through strengthening or improvement, so there is no need to increase the capacity of the structure to meet the seismic demand. This can be achieved by reducing the seismic demand and returning it to the capacity of the structure through various methods such as: increasing ductility, reducing irregularity, or using modern seismic methods including dampers, seismic isolation and mass reduction. There are many ways to improve, and strengthening is one of them.
The improvement is comprehensive and includes almost all components of the structure and can be performed to different degrees and by following the rules of seismic improvement according to the facilities, you can increase or even reduce the safety of the structures, as well as the cost and time of improvement. It can be increased or decreased.
Steps to strengthen concrete buildings
Among the causative factors are poor quality of concrete and the use of inappropriate hardeners, as well as the implementation of inappropriate formwork and the use of low-quality materials, design errors, increased load of the structure and the risk of earthquakes. The building and structure fail and require structural strengthening. It is very important to find different types of damages in concrete structures and they must be strengthened. Some damages that occur in concrete structures such as
Separation of concrete coatings
Creating diagonal cracks in the concrete core
Opening reinforced concrete slabs on discontinuous sides
Creating shear cracks at nodes in the beam-to-column connection
These cases are some examples of weak points that appear in structures and need to be strengthened so that they can have high resistance against earthquakes and other factors. Concrete is a building material with low tensile strength and high compressive strength. If concrete is made without the use of rebar, it will cause cracks in the structure, and this crack may cause the structure to be destroyed and the concrete to disintegrate. Therefore, the use of tensile stiffeners solves this problem.
A concrete building can be strengthened in several ways, and we will explain to you some examples
Reinforcement of concrete buildings by adding shear walls
This method is one of the most common ways to strengthen concrete buildings, which increases the lateral bearing capacity and rigidity of the structure by installing infill walls. Leaving the shear wall open, these walls withstand significantly most earthquake loads. Limits changing the location of the building.
Strengthening buildings using base separation systems
One of the strengthening methods is the use of basic insulators, as this method strengthens the building’s infrastructure against damage such as earthquakes, and also reduces the costs of strengthening and repair. Placing wood between a building’s foundations and walls is one of the techniques that creates resistance against earthquakes. There are many types of foundation tools and they have many advantages.
Another way to strengthen concrete buildings is to reduce the mass of the structure, in this way, by reducing the number of floors of the building, you make it earthquake resistant.
Strengthening the structure using FRP compound
Another way to strengthen concrete buildings is to use polymer composites or FRP, which is one of the newest and most efficient ways to strengthen concrete buildings. In this method, they are used for building and structure members that have weak points. This compound is made by mixing polymer fibers, types of epoxy resin and phenolic resin. Carbon fibers and glass polymers used in composites are widely used in the reinforcement industry. They use the composite method because of its high flexibility in making many types of round and curved surfaces resistant.
conclusion
Seismic enhancement of steel structures is one of the useful methods for strengthening structures and buildings. The purpose of seismic optimization of steel structures is to avoid a lot of damage to structures and buildings in the event of an earthquake.
There are different ways to strengthen concrete structures, such as: adding a concrete wall, using concrete and steel jackets, and using polymer fibers, each of which has advantages. To strengthen and improve buildings, it is better to go to people with experience in this field so that they can carry out your improvement steps well.