Belal AbdelRahman and Khaled Galal
Belal AbdelRahman, PhD candidate, Department of Building, Civil, and Environmental Engineering, Concordia University, 1515 St. Catherine West, Montreal, QC, Canada, belal.abdelrahman@concordia.ca
Khaled Galal, Professor, Department of Building, Civil and Environmental Engineering, Concordia University, 1515 St. Catherine West, Montreal, QC, Canada, khaled.galal@concordia.ca
ABSTRACT
Reinforced concrete-masonry shear walls (RMSWs) with boundary elements (RMSW+BEs) were introduced as a seismic force-resisting system and found to achieve higher ductility levels without sudden loss of their strength compared to rectangular walls. The objective of this study is to investigate, numerically, the sensitivity of the seismic response of RMSW+BEs to the masonry compressive strain at peak stress, εmu, the masonry compressive strength, 𝑓’m, and the vertical reinforcement ratio of the confined masonry boundary elements (MBE), ρvBE, for walls having different cross-section configurations and different aspect ratios. In this regard, a total of thirty
RMSW+BEs are modeled and analyzed using static time history nonlinear analysis to predict the nonlinear seismic response of the RMSW+BEs. Two different aspect ratios, namely 1.66 and 4.16, were investigated, and three different boundary element cross-sections were studied. The selected wall heights (i.e., 6 m (19.69 ft) and 15 m (49.21 ft)) represent RMSW buildings with 2 and 5 storeys, respectively. The results showed that RMSWs with bigger boundary element sizes exhibited more sensitivity to the change of the BE vertical reinforcement ratio and the ultimate masonry compressive strain. On the contrary, it was inferred that walls with higher aspect ratios are less sensitive to changing εmu, and ρvBE. Furthermore, the ultimate lateral capacity of the RMSW+BEs was found more sensitive to the concentrated reinforcement in the boundary elements, whereas the ductility of the RMSW+BEs is highly sensitive to the ultimate masonry compressive strain. This study sheds light on some of the most critical parameters affecting the
design of RMSW+BEs.
KEYWORDS: boundary elements, concrete-masonry, ductility, reinforced masonry, sensitivity, shear walls
