Investigation of infill wall modelling techniques on a substandard reinforced concrete frame

Abstract

Infill walls are mostly considered as distributed load only on the beams in the design and assessment of RC buildings. However, it has been emphasized by many researchers that the infill walls have a considerable impact on the seismic behavior of reinforced concrete frames. The infill walls can cause brittle shear damages at the ends of the boundary columns during the earthquake. The column shear damage can even lead to total collapse of reinforced concrete buildings. Therefore, considering the infill walls in analytical models is essential for achieving realistic structural design and assessment. Hence the infill wall modeling method should satisfactorily reproduce the internal forces that are developed in the frame columns. In this study, the experimental results of an infilled RC frame were used to investigate the effectiveness of infill wall modeling techniques by comparing with the analytically obtained cyclic response of the tested frame. Analytical modelling of infill walls was made by considering four different force-displacement relations and six different geometric modelling techniques. The most appropriate modelling technique is sought through the investigated ones that has the closest results with the cyclic response of the tested frame. Moreover, a parallel two-strut model was proposed as an original infill wall modelling technique.