The 2025 John Adjeleian Lecture

• Hybrid event
• 1301, Health Sciences Building, Carleton University
• 1125 Colonel By Drive, Ottawa, ON, K1S 5B6
• Zoom meeting link

Centre Block Rehabilitation – Structural Highlights

Lecture Synopsis

Centre Block, Canada’s heritage designated federal parliament building, was constructed in 1916 after fire destroyed an earlier building of the same name that occupied the site. The building is currently undergoing a major rehabilitation that includes conservation of its heritage fabric, modernization of its mechanical and electrical systems, enclosure of its interior light courts with glass roofs, the addition of a large multi-level below grade Parliament Welcome Centre, and a comprehensive seismic upgrade. This presentation provides an overview of the existing building along with a summary of its current seismic performance level, key vulnerabilities, and goals of its seismic upgrade.

Centre Block’s seismic upgrade is particularly complex due to the historic materials used in its construction and the heritage finishes that adorn its walls, floors, and ceilings. Two significantly different options for seismically retrofitting the existing structures were studied, namely, a “conventional” scheme entailing the strengthening of the structure to fully resist seismic loading, and a scheme incorporating base isolation to dampen seismic loads to the superstructure. Design was advanced for both options. Although not commonly used in moderate seismic zones, the upgrade incorporating seismic isolation was found to be highly effective, less intrusive and providing a greater level of protection to the building and its finishes.  Base isolation was selected by the Client Public Services and Procurement Canada as the preferred option.

Other significant structural scope components to CB include a general lowering of the basement level; the introduction of  additional basement levels below a large portion of the existing basement; strengthening of all floor diaphragms, including tie-ins to all loadbearing walls; relocation and expansion of elevators and stairs; strengthening of the water and ventilation towers at the rear of the building; and seismic restraint of operation and functional components (OFCs). Structural works on the PT include strengthening.

Speakers’ Bios

Dan Carson joined WSP and legacy Halsall in 1978. Dan graduated from Carleton. He has over 47 years’ experience in structural design and construction of new buildings, investigation and restoration of existing buildings. Dan is the Lead Structural Engineer on the Centreblock project and has worked on the project since the first day of the project.  Dan has a particular interest in Seismic design and has been a member of the National Building Code of Canada Standing Committee for Earthquake design over the past 20 years.  In 2010 Dan volunteered as part of a pro bono joint venture of Canadian Consulting engineers that contributed to the design and construction of 8 new schools in Haiti to replace schools that were destroyed by the Earthquake. The project won numerous awards. Dan has worked primarily in Ottawa and has been responsible for many notable projects including the renewal of the Museum of Nature, The restoration of the War Memorial, and numerous projects on Parliament Hill.

David Arnold is a Principal Structural Engineer with WSP and has over 20 years experience in structural design in New Zealand and Canada. Dave is a specialist in the seismic design of new buildings and the assessment and seismic upgrade of existing buildings. In his current role, David is the senior technical manager of the structural design for the Canadian Parliament rehabilitation.