For various reasons such as changing the use of the building, low strength of concrete, poor execution or design or adding floors, building owners face structural problems and sometimes legal obstacles and lack of approval of the supervising engineer or the organization of the engineering system. Maintaining strength and non-vulnerability and maintaining safety for the structure itself and humans need to strengthen and strengthen the main and fundamental components of the building.

Non-structural components include all components and contents inside the building except structural parts such as beams, columns, floors, etc. Common non-structural components in buildings include suspended ceilings, windows, office supplies, computers, shelves, drawers and drawers, heating, refrigeration and ventilation equipment, electrical appliances, furniture, lamps and chandeliers. Non-structural components are usually not analyzed by structural engineers, but by architects, mechanics, electrical engineers, or interior designers to determine their type and characteristics; Or, without the intervention of a professional designer, purchased and installed by landlords or tenants after construction.

Considering the performance of structures during earthquakes in recent decades, it has been observed that the performance of non-structural components play an important role in the operation of structures after an earthquake, for example in a hospital False ceilings or collapsed walls are inefficient, or in a residential building, due to the lack of use of wall posts, the walls may not engage with the columns and may collapse during an earthquake, causing severe damage due to the non-structural walls. Homeowners can reduce the loss and damage caused by the collapse of non-structural components by strengthening and strengthening non-structural components in the building.

Concrete structures as a large part of the structures, if designed and executed according to accurate calculations and ductility relationships, will be very desirable buildings, but the quality of construction in some structures is very poor for various reasons.

Poor quality of concrete, improper reinforcement, poor execution of concreting, substandard materials, design errors, execution errors, increased structural load, the impact of destructive environmental conditions and earthquake risk in most parts of Iran are among the factors that weaken concrete structures and the need They strengthen the building.

Many existing reinforced concrete structures, designed and implemented in accordance with pre-1970 regulations, have poor reinforcement details that cause problems such as low lateral displacement capacity, low energy dissipability, deterioration of the mechanism and the occurrence of unreacted mechanisms in the mechanism. All these cases lead to the collapse and destruction of the structure. Deformable details in a reinforced concrete structure in the form of such things as poor shear strength of the joint due to lack of transverse reinforcement in the joint, low shear capacity of the column leading to the joint, short overlap length of the column longitudinal reinforcement, non-observance of compression fitting Beam reinforcements are present in the connection area. Weakness in the area of ​​joining the beam to the column together with the undesirable factor of the weak column-strong beam endangers the stability of the structure. The occurrence of the mechanism in the beam is preferable in comparison with the column and the column mechanism is more non-critical in comparison with the connection area. The appearance of the mechanism and the formation of the joint in the area of ​​joining the beam to the column, has led to increasing periods in the beam and column, which causes the loss of bearing capacity of the column and affects the safety of the structure.

One of the oldest and most common types of buildings are buildings, so the reinforcement of a building is of special importance. As 30 out of 30 doors in buildings

Steel buildings, if properly designed and executed, have very good strength and ductility, but due to the lack of use of specialized executive forces and erroneous assumptions, the construction of steel buildings has disadvantages and problems that need to be strengthened and It has improvements. Steel buildings are often damaged and do not function properly under seismic loads due to local buckling. Or they need to be reinforced due to corrosion. In this article, an attempt has been made to strengthen steel buildings against seismic and gravity loads.