Progressive Collapse Analysis of Reinforced Concrete Frames with Unreinforced Masonry Infill Walls Considering In-Plane/Out-of-Plane Interaction

Reinforced concrete (RC) frames with unreinforced masonry (URM) infill walls are commonly used in seismic regions around the world. It is recognized that many buildings of this type perform poorly during earthquakes. Therefore, proper modeling of the infill walls and their effect on RC frames is essential to evaluate the seismic performance of such buildings and to select adequate retrofit methods. Using damage observations of RC buildings with URM infill walls from recent earthquakes, this paper presents a new approach to consider in-plane/out-of-plane interaction of URM infill walls in progressive collapse simulations. In addition, the infill wall effect to induce shear failure of columns is simulated with a nonlinear shear spring modeling approach. The research endeavor is accompanied by implementation of the developed modeling aspects in the publicly available open-source computational platform OpenSees for immediate access by structural engineers and researchers.