Strengthening the building

Based on studies conducted in the last two decades, as well as existing scientific documents and observations from the twentieth century, Iran is considered one of the most active regions in the world in terms of earthquakes.

The fault located in this area exposes Iran to strong and dangerous earthquakes, which is why it is very important to pay attention to its principles and standards in urban construction.

Currently, with every earthquake, we are witnessing huge human losses in different areas, especially in rural areas. Therefore, Iran is considered one of the seismic countries in terms of the number of earthquake victims

Although humans with their current knowledge and facilities are still vulnerable to very severe earthquakes, but by increasing the level of information and public awareness about earthquakes, promoting safety principles and assessing the vulnerability of buildings, it is possible to satisfactorily prevent injuries and damage caused by earthquake.

Today, by identifying weak points in buildings and implementing safety and strengthening protocols, especially in densely populated cities like Tehran, we can be better prepared to deal with severe earthquakes in the future.

What does strengthening a building mean?

In general, the concept of building strengthening, in terms of civil science, refers to increasing and strengthening a structure’s resistance to a variety of stresses, which often include natural factors.

One of its most important applications is to increase the strength of buildings against earthquakes. In fact, it is known as one of the methods of seismic improvement of structures, which has significant effects on increasing the strength of structures and can be implemented in different ways.

Due to the location of our country in the earthquake-prone area, improvement in Iran is an issue of undeniable importance and is one of the vital points in construction.

Reasons for the need for strengthening

There are many reasons to do structural strengthening. We see all over the world that many buildings have weak spots; But despite the differences in these weaknesses, they can be eliminated only by implementing them and the strength of buildings can be increased and reconstructed in a principled manner using modern methods.

Some of the weaknesses of building structures are:

1- Design error:

An error in the design of structures, in fact, means problems in preparing plans, ignoring basic principles, incorrect and erroneous forecasts. In such cases these defects created in the early stages of construction can be eliminated.

2- Implementation error:

Errors that occur in execution are generally the same as problems that occur in formwork, concrete, and the like. Such problems are often caused by a lack of supervision, the presence of unspecialized forces in the process, or the use of cheap and low-quality materials.

3- Change user:

Sometimes, for some reason, the use of structures is different and the expectations for using the structures are different. It is this change in use that makes buildings need to be strengthened, as the load exceeds expectations and the structure does not have sufficient strength.

4- Reconstruction:

In many cases, we see that the design of buildings is outdated and no longer as strong as new structures. In this case, we must increase the ability of old buildings as much as new structures against incoming forces by implementing improvements.

Strengthening the building and industrial structures

With the aim of reducing the risk of earthquakes in the country, the government has introduced various programs to study and strengthen important government buildings, as well as industrial structures and facilities that are the vital arteries of the country’s economy.

An important aspect of these programs is the need to use computing software with the required structural strength and hardware, including modern and durable building materials and the use of new structural strengthening techniques. To achieve this, the eleventh government identified plans for training individuals, both in the design department and implementing contractors.

Concrete slabs and concrete buildings are reinforced by Bhikran Sazan Shamal Company. For a free consultation and price inquiries, call 88797928-021

The importance of strengthening buildings in Tehran

A 5.2 magnitude earthquake in the fall of 1996 in western Tehran Province caused many geologists to take the “big earthquake” theory in Tehran more seriously. This incident also led to a serious change in the approach to strengthening brick buildings in Tehran.

Based on the estimates of geologists and also according to the records of Tehran earthquakes, it can be obtained that every 150 to 200 years a large and severe earthquake occurs in this region, and therefore we are now in a period in which we must prepare ourselves to prepare for a large earthquake.

Although some well-known seismologists in Iran somehow reject these estimates, the 29th Azar earthquake in Mallard City and also the Mahdasht earthquake south of Karaj have caused speculation about the activation of the fault in the northern areas of Tehran again. Intensification. Based on previous speculation, it is expected that with increasing pressure in the North Tehran Fault, there is a possibility of an earthquake with a magnitude higher than 7 Richter.

Interestingly, just a few days after the Tehran and Karaj earthquake, many people searched the Internet for methods of strengthening and strengthening structures, strengthening beams and columns, strengthening concrete, and strengthening concrete buildings using FRP materials. This claim can also be proven by using Google Trends.

Definition of resistance by seismic improvement

Every structure has seismic requirements and if the capacity of the structure does not equal its seismic requirement, it will be subject to lateral loading or pressure. In optimization, the goal is to use the described methods to bring the capacity of the structure as close as possible to its seismic needs.

If we want to increase the capacity of the structure, the so-called strengthening process is performed for the structure. This process can be done by increasing the hardness or increasing the strength. The capacity of the structure can be increased using arches, shear walls or concrete jackets.

Sometimes, the seismic requirement of a structure can be reduced to equal the amount of capacity of the structure. Thus, there is no need to increase the capacity of the structure. This can also be done by increasing ductility, reducing mass, reducing irregularities and using new techniques such as damped seismic separation.

Therefore, it can be concluded that strengthening is actually one of the seismic improvement methods that with the help of a process is set to rehabilitate existing structures, preventing damage and collapse of the structure against additional loads or destructive environmental factors.

Various methods of strengthening buildings and structures

With FRP material

FRP stands for fiber reinforced polymer. It is a hybrid product consisting of two parts, fiber and matrix. Among the fibers used in manufacturing this type of material are carbon, glass and aramid.

With curved frame

Bending frames, unlike arches or shear walls, have no additional members and therefore have little resistance to lateral deformation. This helps the structure to deform against earthquake lateral loads such as wax and prevents severe damage.

With shear wall

In this method, by attaching the shear wall to the concrete structure, the rigidity of the structure can be increased to the required extent, and by increasing the load-bearing capacity, the ability of the structure to bear lateral loads caused by earthquakes is also increased.

Clips or braces  for strengthening

Brackets or braces are effective components that are made diagonally into the capacities of permeable structures and significantly increase the resistance of the structure against lateral loads. The design of the arches is actually inspired by the triangle structure. Like a triangle, the angles between them always remain constant if the lines composing them do not change, and if the arcs are attached to a fixed support, they are very resistant to external forces such as strong earthquakes. This is the same property as the luggage compartment components.

Concrete column with FRP composite

The use of FRP fibers in columns increases the shear capacity and the rupture of the structure changes from shear to bending. This significantly increases the ductility of the structure against lateral loads and as a result, in addition to greater resistance to earthquakes and corrosion, they also show good resistance.

Improving the building structure system

In the seismic improvement of building structures, three common methods are used shear wall, bending frame, seismic separator, damper and braces, each of which has its own advantages.

Use of retarder to strengthen the building

Buildings with a large number of floors need more efficient solutions. Damper is a special equipment to absorb the energy entering the structure which absorbs the destructive effects of earthquakes and does not allow the building structure to be damaged.

The role of seismic insulation in improving the building

Using a seismic isolation system is a common way to improve a building and protect it from earthquakes. This system includes structural components that separate high-rise buildings from the foundations placed on the seismic base, thus providing the building with higher seismic resistance.

Concrete slabs and concrete buildings are strengthened by   Bikaran Sazan Shamal Company. For a free consultation and price inquiries, call 88797928-021

Advantages of using FRP

The use of FRP composites in the material adds special properties to it. These types of composites are always a consideration in modern building strengthening methods and can increase the overall resistance of a building against severe earthquakes at a low cost. Here are some important benefits of using FRP in buildings.

High tensile strength

High resistance to corrosion and adverse environmental conditions

Less weight than steel
Magnetic permeability
Ability to use externally
Easy charging and fast operation
The ability to be used in different materials and the ability to produce in different shapes
Reinforcing concrete columns

Reinforced concrete for concrete columns is perhaps the most common material used to strengthen buildings.

Contrary to some people’s beliefs, concrete is not just reinforced cement, but cement is only part of the composition of reinforced concrete. The standard composition of reinforced concrete includes cement, water, aggregate and steel.

Concrete steel composites are versatile and durable composite elements in the construction industry. Composite materials generally have better properties than their individual components.

As mentioned earlier, concrete without rebar performs well under compression but has little tensile strength.

Steel has high tensile strength but is not resistant to oxidation due to exposure to moisture.

By combining these two materials, concrete and steel composites have high compressive and tensile resistance, while the rebar beneath the strong concrete layer is protected from oxidation.

Composite panels, beams and columns of these materials are widely used in various construction and building strengthening projects and are known for their stability and durability.

Strengthening beams

Steel beam reinforcement may be uncommon in residential construction projects, but it is essential in high-rise buildings and skyscrapers.

Steel has excellent compressive and tensile strength, ductility and toughness, making it one of the leading materials used in various construction projects and strengthening of industrial and commercial buildings.

Contrary to popular belief, steel is generally cheaper than concrete because most of the steel produced today is recycled or A992 steel.

Recycling steel is less expensive and more complex than producing steel from newly mined iron ores.

The impressive overall strength of steel and its relatively low weight make it easy to install. Steel girders can also be easily mass-produced, especially if several similar steel girders are needed for construction or strengthening.

Reinforcing buildings with steel is very common, allowing for further design, construction or strengthening.

Steel has great ductility and compatibility to be formed into various shapes. Steel beams and columns are formed using hot rolled steel.