1 PhD candidate, Department of Civil Engineering, University of British Columbia, Vancouver, BC, Canada, centeno@civil.ubc.ca
2 Professor, Department of Civil Engineering, University of British Columbia, Vancouver, BC, Canada, ventura@civil.ubc.ca
3 Faculty, Department of Civil Engineering, British Columbia Institute of Technology, Burnaby, BC, Canada, sbrzev@bcit.ca
4 Professor Emeritus, Department of Civil Engineering, University of British Columbia, Vancouver, BC, Canada, dla@civil.ubc.ca
ABSTRACT
Current Canadian masonry design provisions for seismic design contained in CSA S304-04 standard of reinforced masonry (RM) shear walls often shows that sliding shear is the governing failure mechanism for squat walls with a height/length (H/L) aspect ratio below 1.0 at low axial load levels and subjected to lateral seismic forces and overturning moments. As a result it is estimated that the sliding shear mechanism prevents the development of ductile flexural response in these walls. However, previous experimental studies have shown cases of similar RM squat walls that have initially responded with a flexural yielding mechanism and after cycles of inelastic rotation have developed a sliding shear failure mechanism. Despite these observations, there currently are no recommendations on how to estimate the seismic performance of a RM squat wall with a sliding shear mechanism for a seismic design. The following presents the progress in a research study to model the sliding shear mechanism as a function of changes in friction resistance, dowel action and flexural hinging. This rationale model has been used to recreate the results observed in an experimental test and determine how the sliding shear resistance varied during the loading history.
KEYWORDS: reinforced masonry, sliding shear, seismic response, shear walls, squat walls
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