Reinforced Masonry Building Seismic Response Models for ASCE/SEI-41

Abstract

The development of models to predict the inelastic behavior of the individual components of a building system at different performance levels is an essential step in performing nonlinear static and dynamic analyses, as recommended by ASCE/SEI-41. However, current methodologies for generating nonlinear models for reinforced masonry shear wall (RMSW) buildings do not adequately account for various system-level aspects, such as the influence of the floor slab stiffness. Several recent studies have shown that these aspects would significantly alter the overall building response under seismic loading. In addition, although ASCE/SEI-41 defines the capacity parameters of reinforced masonry shear walls (RMSWs) with rectangular cross sections through standardized force-displacement backbone relationships, no corresponding relationships are available for RMSWs with boundary elements. Moreover, ASCE/SEI-41 does not provide the necessary hysteretic parameters required to define the cyclic behavior of any type of RMSWs under seismic loading. To address these issues, this study focuses on developing two ASCE/SEI-41 relevant models for RMSW buildings, based on the currently available provisions pertaining to their reinforced concrete (RC) counterparts. The first model is a backbone model for RMSW buildings without and with boundary elements that can be used to perform nonlinear static analyses. The experimentally validated modeling approach shows that RC parameters are applicable, but it is critical to include the out-of-plane stiffness of the floor diaphragms when evaluating the overall building response. The second model is a concentrated plasticity (spring) model in OpenSees used to simulate the hysteretic response of RMSW buildings with different configurations, to conduct nonlinear dynamic analyses. Finally, the developed numerical hysteretic responses are compared with experimental results in terms of the most relevant characteristics, including the initial stiffness, peak load, and stiffness and strength degradation as applicable. This study aims at presenting useful system-level response prediction tools for the nonlinear static and dynamic procedures specified by ASCE/SEI-41.