Effect of infill wall modelling techniques on the seismic response of a reinforced concrete frame

In our country and throughout the world, the infill walls are mostly considered as distributed load only on the beams in the design and assesment of RC buildings. However, it has been emphasized by many researchers that the infill walls have a considerable impact on the seismic behaviour of reinforced concrete frames. The infill walls can cause unexpected brittle shear damages at the ends of columns during earthquakes. The column shear damage can lead to total collapse of reinforced concrete buildings. Therefore, inclusion of infill walls in analytical models is essential. In order to be able to incorporate the infill walls into the reinforced concrete calculations, the infill wall modeling method should satisfactorily reproduce the internal forces that are developed in the frame columns. In the thesis study, the experimental results of an infilled RC frame were used to investigate the effectiveness of infill wall modeling methods by comparing the pushover curve and cyclic response of frame columns. Then, the most effective infill wall modeling was employed for investigating the seismic behaviour of an actual RC frame with infill walls. Modal analyses and nonlinear response history analyses were conducted on the selected RC frame to investigate the effect of infill walls on its seismic response. The comparisons were made in terms of inter-story drift ratio, peak floor accelerations, storey shear forces and the plastic hinge distrubitions. It is revealed that infills can affect the seismic response of RC buildings considerably. The true seismic behaviour can only be reproduced with a representative infill wall modeling method.