Determining seismic performance of reinforced concrete structures with infill walls for different ratio and configuration

In the design and analysis of the structures in modern-days, the effects of infill walls that are defined as non-structural elements on the building performance are ignored. However, infill walls affect the structural characteristics of the structures such as stiffness, ductility, mode shapes, damping and periods. It is thought because infill walls are not taken into consideration in calculations, it is stayed the safe sides. However, the layout and ratio of the infill walls in the floor may cause some irregularities such as torsional irregularity, short column, weak and soft story irregularity. Therefore, the infill walls should be considered for the actual structural behavior, in the design and analysis of the structures. In this study, the effects of infill walls with different ratio and layout on the seismic performance of reinforced concrete structures were investigated. For this purpose, a reinforced concrete structure was designed according to the Turkish Earthquake Code-2018. Equivalent earthquake load method that is one of linear analysis method was used in the design of the structure. In the analysis, 5 different ratios and layouts of infill walls were taken into account. The nonlinear analyses and performance assessments were performed by using time history analysis with ground motion records which were selected according to TEC-2018. 11 ground motions used in the analyses were selected considering some parameters such as near and far fault effects, Turkey's fault mechanism. The selected ground motion records were scaled by using simple scaling method to be compatible with the horizontal elastic design spectrum. The finite element models and nonlinear time history analyses were performed with SAP2000 structural analysis program. RESPONSE2000 program was used for section analysis and moment-curvature relations. As a result of the analyses, mode shapes, periods, base shear forces, story drift ratios and performance levels, which were obtained for the different infill walls ratio and layouts, were examined, comparatively. As a result of the analyses, it was observed that the infill walls provided significant reductions in the period values and relative displacement of the buildings. Moreover, ıt was determined that the infill walls provided significant contributions for earthquake performance of the buildings.