The Evolution of Performance-based Seismic Design of Bridges in Canada

Description

Distinguished Webinar Series

Organized by the Canadian Association for Earthquake Engineering and Seismology

The Evolution of Performance-based Seismic Design of Bridges in Canada

Date: Wednesday, April 9, 2025, Time: 3:00 p.m. ET, 12:00 p.m. PT

Abstract

The seismic design of bridges in British Columbia has followed international evolving practices since the early 1980’s. Circa 1990, the Province of BC embarked on a bridge retrofit program including the Vancouver region’s nine major river and harbour crossings. These projects drew on local engineering skills plus technical expertise from internationally recognized experts in structural and geotechnical engineering. The seismic design of new bridges in BC also evolved with the development of modern seismic design tools and methods, and from their application to these technically challenging retrofit projects. The 1990’s retrofit phase in BC targeted collapse-prevention upgrades to major bridges built in the 1950’s to 1970’s. This “Safety” retrofit was phase 1 of a planned two-phase retrofit program, with ‘functional’ seismic upgrades to follow. In recent years, the higher-level “functional” retrofit objective came back into focus. Engineers, planners and governments learned lessons from recent earthquakes and of the importance of designing for a rapid return to service for our transportation networks after large earthquakes. Hence the Ministry is currently reviewing the implications of functional-level upgrade needs, costs and benefits to inform the design and construction of additional retrofit works. During this time, performance-based seismic design philosophies (PBD) gained traction and increased in practice. BC embraced PBD on projects in the early 2000’s, and the Canadian bridge code formally adopted PBD in 2014, which has continued in the coming 2025 bridge code.

This presentation will describe the evolution of seismic bridge design and construction in BC and other regions of Canada. It will highlight challenges faced as well as some remaining challenges and opportunities provided through performance-based approaches and network-level considerations. It will show through case studies how functional retrofits can be achieved and how corridors can be assessed for importance in post-earthquake response.

It will also provide an overview of the evolution of PBD within our coming 2025 bridge code and will discuss issues and challenges in PBD in practice. It will discuss aspirations for improvements to PBD for structural and geotechnical design, including needs for refinements in seismic hazard information to better suit PBD of bridges and buildings for the next code cycle.

Presenter 

Don Kennedy, P.Eng. Senior Bridge Engineer Associated Engineering Ltd. (kennedyd@ae.ca) CAEES-ACGPS Vice-President

Don has 40 years of experience in the planning, design and construction of new bridges, bridge and structure rehabilitation and seismic retrofit, bridge evaluation, forensic investigations into bridge failures. His experience includes Canadian and international engineering experience in earthquake engineering. He has authored papers and presented seminars on seismic design and retrofit, codes and performance-based design and rehabilitation. During his career he has worked on the design or design reviews of most of the major bridge retrofit projects undertaken in BC since the early 1990’s. He led the retrofit design of the Oak Street, Knight Street and Mission Bridges, and provided technical guidance to the Cambie and Granville St Bridge retrofits, and to a recent seismic resilience assessment of the Highway 99 corridor between Vancouver and the USA border. These projects influenced seismic retrofit practice and policy in BC and Canada. Most recently he has worked with owners and engineers in Ontario and Quebec on seismic projects, standards and policy, in part arising from the recent increase in seismic hazard as part of the sixth generation ground motion modelling and hazard mapping in eastern Canada, and to assist owners in the application and management of performance-based seismic design for new bridges and seismic retrofit projects/

Don has contributed to the Canadian Highway Bridge Design Code (CHBDC) for seismic design since 2002 and is the current Chair of TSC 4 for the Seismic design of bridges. He is currently a Director and Vice-President of the Canadian Association of Earthquake Engineering and Seismology. He contributed to the application of performance-based seismic design implemented into the CHBDC in 2014, 2019 and the coming CSA-S6:25 in summer 2025.

To receive a Certificate of Attendance for this webinar, please take note of the following guidelines:

1. Register individually to receive your own link to join the webinar.
2. During the registration, specify the full name that is to appear in the certificate, and use the email address to which the certificate is to be sent.
3. On the day of the webinar, use your own link to join to be properly logged into the attendance list.
4. Minimum attendance of at least 30 to 45 minutes (which is the typical length of the main lecture) is required in order to be eligible for the certificate.