Banting, Bennett;1 Drysdale, Robert;2 El-Dakhakhni, Wael3 and Stubbs, David4

1 Masonry Research and Development Engineer, Canada Masonry Design Centre, 360 Superior Blvd., Mississauga, ON, Canada, Bbanting@canadamasonrycentre.com
2 Chair, CSA S304 and Professor Emeritus, Department of Civil Engineering, McMaster University, Hamilton, ON, Canada, drysdale@mcmaster.ca
3 Member CSA S304, Chair S304 Seismic Design Working Group and Martini Mascarin and George Chair in Masonry Design, Department of Civil Engineering, McMaster University, Hamilton, ON, Canada, eldak@mcmaster.ca
4 Vice Chair, CSA S304 and Director, Canada Masonry Design Centre, 360 Superior Blvd., Mississauga, ON, Canada, dstubbs@canadamasonrycentre.com

ABSTRACT
The most significant change to CSA S304-14 is the creation of the new Clause 16 Special provisions for seismic design. This clause contains all provisions related to seismic design of masonry. The Limited ductility shear wall seismic force resisting system (SFRS) category has been removed and a Conventional construction shear wall SFRS category has been defined and consolidated to  include sites of high seismic hazard indices. Moderately ductile squat shear wall SFRS now provides designers with clear directions on the detailing requirements of flexurally controlled versus shear controlled mechanisms. Moderately ductile shear walls now permit partialgrouting of the plastic hinge region under certain circumstances. A new ductile shear wall category has been included with a Rd = 3.0 and Ro = 1.5 as well as explicit calculations for the inelastic rotational demand and capacity of the plastic hinge region for moderately ductile and ductile shear walls. Finally, design provisions have been provided for the use of masonry boundary elements as a means to increase the usable masonry compression strain, εmu.

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