Evaluation of participation of masonry infill walls in the linear and nonlinear behaviour of RC buildings with open ground storey

Abstract

In the present study, assessment of contribution of masonry infill wall in the linear range as well as exploration of post peak behaviour of RC buildings with open ground storey is targeted. Three different scaled RC building models having open ground storey and with different sizes of opening on infill walls have been tested on a shake table with low intensity of input excitations. Using acceleration response from these models, structural parameters have been identified adopting a system identification technique. The storey lateral stiffness in the linear range has been estimated using the above-mentioned identified modal parameters and an expression for stiffness representing the contribution of the masonry infill wall in the form of a diagonal strut has been proposed. Numerical models of all the specimens tested on shake table have been simulated. These numerically simulated models with different configurations have been used for assessment of post elastic behaviour of RC building models. While the lateral stiffness in the elastic range as well as peak load carrying capacities have been observed to increase in all the models due to the presence of infill wall, some interesting observations have been noted for shear force distribution across floors and possible reasons of failure of building with soft storey. Further, it has been observed that for a particular area of opening in the infill wall, the location does not considerably influence the load-displacement response of the building system.