Evaluation of code provisions for design of medium rise buildings supporting brick veneer wall systems under the effect of in-plane seismic loads

Abstract

The seismic performance of masonry veneer wall systems has come under increasing scrutiny in the past few years. As part of this scrutiny an investigation evaluating the interaction of masonry veneers and medium rise structural frames under seismic loads was conducted.In this investigation, the in-plane interaction of structural frames and masonry veneer wall systems are evaluated. The responses of the medium rise building system to seismic loading are compared using a mass representation of the masonry veneer wall system (as is allowed by design codes) and by a more accurate strut and frame model. These building frame-wall system models were subjected to the design based earthquake (DBE) and maximum considered earthquake (MCE) levels of selected ground motion. A parametric study was conducted that encompassed the range of stiffness and strength of both the frames and the wall systems encountered in common construction practice in the United States.The paper will present a summary of the effects of the veneer wall systems on the response of the building frames that support them, when loaded in their in-plane direction, during a seismic event. It will be shown that at the extremes of stiffness that bound the response of veneer wall systems, the prescriptive code requirements can significantly over estimate the effect of the wall systems when these are incorporated into highly flexible structural frames and can produce slightly unconservative results when addressing masonry veneer walls in very stiff reinforced concrete shear wall systems.