Development of Canadian Seismic-Resistant Design Code for Reinforced Concrete Buildings

This paper summarizes the developments and changes to the seismic design provisions of the National Building Code of Canada (NBCC 1990) since its 1977 edition and discusses the changes to the seismic design provisions of the Canadian Standards Association Standard, Design of Concrete Structures for Buildings (CAN3-A23.3). The paper outlines the philosophy of seismic-resistant design of the Canadian code, discusses the changes to the zoning maps, static design procedures, and the introduction of the force modification factors. The paper also deals with the changes to the Canadian reinforced concrete code and especially with the section on ductile walls, changes to load combination factors, and the explicit links between the concrete code sections containing the detailing requirements and the NBCC sections on determination of the design seismic forces.