Analyze of a damaged rc building with irregularly distributed shear wall

The building stock in our country has been built both architecturally and statically with designs that are unsuitable for the basic principles of earthquake engineering, and such structures have suffered considerable damage in major earthquakes. These buildings are extremely irregular and have low strength and ductility. These shortcomings are not only seen in residential buildings, but also in public buildings. The earthquake reliability of such buildings should be determined and the unreliable structures should be strengthened rapidly. As a very useful and practical solution to increase the lateral strength, the shear wall can be added to the structural system. Many studies have shown that shear walls greatly increase the lateral load carrying capacity. However, the behavior of the system can be improved if the shear walls used in the structural system provide certain conditions in strength and ductility. One of the shear walls of the old service building of the Antalya Provincial Administration suddenly collapsed. This 17-storey building is reinforced concrete building with frames and shear walls. Architechtural plan of the building is V shaped and materail quality and structural system desing is very low. Damage can not be prevented even though there are large shear walls in the building. It is not known how this building, which has been damaged without an earthquake, will behave under the effect of an earthquake. In this study, this damaged building was modeled analytically in SAP 2000 program and capacity and contribution to earthquake behavior of the building of shear walls were investigated. For this purpose, both linear and nonlinear methods were used to analyze the system and evaluate the shear walls. Mode Superposition Method is used in linear method and Time History Analysis is used in nonlinear method. Plastic hinges were assigned to structural elements to define the nonlinearity. In the considered building, it is seen that the damage occurred in the shear wall is the shear damage. Therefore, in the analytical model, shear hinge also described to shear walls with moment hinge. 7 ground motion records were used in Nonlinear Time History Analysis (NTHA) and these records were scaled to design spectrum which is given in Turkish Seismic Code 2007. Shear walls shear forces obtained by both linear and nonlinear methods are compared with shear capacities of shear walls and it is seen that existing shear walls are insufficient. the damaged shear Wall had firstly shear damage in NTHA and the program could not continue to analyze after the shear damage occurred. A nonlinear analysis, which is already classically described by simply describing the bending hinge, will result in incorrect results, especially in low strength and ductility. Because, if the shear damage occurs before bending damage, the program will not detect this damage and it will continue to analyze as if the shear wall is not damaged. As a result, shear walls with low strength and ductility may make the building worse, as opposed to improving the earthquake behavior. In the nonlinear model of the shear walls, it is more appropriate to describe both the bending and shear hinge together, in case it is not determined which of the shear or bending damage will occur first.