Numerical study of the seismic performance of fully grouted reinforced masonry shear walls with boundary elements subjected to dynamic loading

Abstract

Reinforced masonry shear walls with boundary elements (RMSW + BEs) have enhanced curvature and displacement ductility and more energy dissipation than their rectangular counterparts when subjected to quasistatic cyclic loading. However, the behavior of walls tested under quasistatic cyclic loading is different from that under dynamic loading. Although there are many studies in the literature regarding the seismic response of RMSW + BEs, there is a gap in understanding the seismic performance parameters of RMSW + BEs when subjected to dynamic loading. Therefore, in this study, a numerical investigation of the seismic behavior of twelve previously tested half-scaled fully grouted RMSW + BEs was performed to quantify the seismic performance parameters of the walls under quasistatic cyclic loading and incremental dynamic loading. The studied walls have different design parameters that cover different aspect ratios, applied axial stress, horizontal and vertical reinforcement ratios, confinement type in boundary elements (BEs), discontinuity in BEs at upper floors and the presence of interstory slabs. A 2D numerical macromodel was developed using the Extreme Loading for Structures (ELS) software to validate and simulate the nonlinear lateral cyclic response of the studied walls. A nonlinear time-history analysis (NLTHA) was carried out using seven pairs of simulated ground motion records developed by Atkinson to represent Eastern Canada earthquake regions (i.e., Montreal, Quebec). The results showed good agreement between the walls’ results among the two loading protocols to better estimate and correlate the walls’ dynamic performance from quasistatic cyclic testing. The quasistatic loading results showed conservative lateral performance compared to dynamic loading in terms of stiffnesses, lateral capacity and energy dissipation. Moreover, the effect of different design parameters has been inspected on the dynamic performance of RMSW + BEs. Increasing the wall aspect ratio led to lower wall stiffnesses and lateral capacities at different loading stages. More energy dissipation and lateral capacity levels were observed when utilizing higher axial stresses on the walls. This study's findings will help better predict and estimate the lateral behavior of RMSW + BEs to help develop subsequent editions of the North American design standards for masonry structures.