Seismic Demand of RC Moment Frames with Infill Masonry Walls

Infill masonry walls are commonly constructed in the exterior frames of RC moment frame buildings. Their effects on the behavior of the RC moment frame buildings typically are ignored during design process. This study investigates the effect of infills on seismic characteristics of RC moment frames. A typical 4-story intermediate RC moment frame was designed for a specified seismic hazard level and satisfies the minimum requirements of relevant codes. To evaluate the effects of infills, masonry walls are added in exterior frames. A nonlinear 3D analysis was performed to determine maximum plastic rotations, plastic hinge formation pattern, drift demand, lateral stiffness and strength. The results were compared with the behavior of the initial RC moment frame without infills. The results show significant differences in seismic demands of the entire structure, such as decrease in drift and ductility.

Keywords:

infill masonry wall , seismic demand , RC moment frame , nonlinear analysis.