Seismic design and performance of steel moment resisting frame buildings designed using NBCC 2005

Currently the building code authorities in many jurisdictions including Canada feel that a performance-based design approach should be used to ensure that the structure has adequate strength and deformation capacities. Although the National Building Code of Canada (NBCC 2005) is not yet a fully performance-based code, it presents an objective-based format which incorporates some concepts of the performance-based design. It provides a force-based seismic design approach, where the displacement capacities are provided indirectly. The current research focuses on the performance of a set of five, ten, fifteen and twenty storey steel moment resisting frame buildings designed according to the seismic provisions on NBCC 2005. A series of static and dynamic analyses have been carried out to evaluate their performance. It has been observed that the assumed ductility capacity in the force-based design may not always be achievable, and the capacity of the building, under seismic force decrease, with the increase of building height. Also the nonstructural element has a great effect on the performance of the structure and it decreases the drift demand. The thesis also examines a number of simple methods available for performance-based design of buildings and implemented some of them for one of the buildings considered here. It has been observed that the design base shear calculated for a target damage parameter or drift demand, varies based on the method used. Further studies are needed to develop a robust method for performance-based design within the context of the Canadian code.