Alexandra Bridge Coating and Steel Repair Project

Background

The Alexandra Bridge, also known as the Interprovincial Bridge, connects Sussex Drive in Ottawa and Boulevard des Allumettières in Gatineau. It provides a link between the tourist attractions of the Byward Market and the Museum of Civilization. The structure has been designated by the Canadian Society of Civil Engineers as a “National Historic Civil Engineering Site.” The bridge is owned by the Government of Canada and maintained by Public Works and Government Services Canada (PWGSC).

The Alexandra Bridge currently transports approximately 22,000 vehicles per day, amounting to 13 percent of the National Capital Region's interprovincial vehicle bridge traffic. It is also used by about 40 percent of all pedestrians and cyclists—the highest use among all interprovincial bridges.

Upcoming activities

Over the next year, the North Hull Trestle of the structure will be given a new coat of protective paint, designed to prevent steel corrosion. Minor steel repairs may also be undertaken, should deficiencies be detected during the coat preparation work. The construction work is expected to be completed by the end of 2013.This work supplements the rehabilitation work done on the Alexandra Bridge in 2009 and 2010, which extended the service life of the bridge and included structural improvements to ensure its functionality, while preserving much of its original features and heritage character.

Scope of previous rehabilitation activities

Third-party condition/inspection reports, carried out every year, along with ongoing maintenance, ensure the safety of this bridge, which was built between 1898 and 1901. The bridge underwent a major rehabilitation in 1975, when all deck areas were replaced to accommodate the present lane arrangements and configuration. The bridge was repainted in 1995. While ongoing maintenance extended its service life, a major rehabilitation was required in 2011.

The rehabilitation involved:

• strengthening and retrofitting the steel structure and piers, and increasing their seismic capacity;
• replacing the 575-metre-long centre lane concrete deck and guardrails;
• replacing the wooden boardwalk and railings;
• installing inspection walkways; and
• installing damping mechanisms to reduce the vibration of the structure.

Rehabilitation activities – Chronology of events

The rehabilitation activities were completed in the spring of 2011 and the project was delivered on time, on scope and on budget.

Work completed in 2009

Work began in the spring of 2009 with the strengthening and retrofitting of the steel structure, as well as the seismic upgrade of the piers and abutments.

Work completed in 2010 and early 2011

The replacement of the 575-metre-long centre lane concrete deck (Ottawa-bound traffic lane) and guardrails started in the summer of 2010. As part of the rehabilitation project, the centre lane of the Alexandra Bridge was scheduled to be closed only during its replacement. However, due to difficulties encountered with the seismic retrofitting of one pier, a complete closure of the bridge was required for this portion of work, rather than the planned night and weekend closures. The centre lane was closed for 26 weeks (April to October 2010)—an additional 9 weeks on top of the 17 weeks initially scheduled. During this period, the bridge's one remaining lane remained opened to either Ottawa- or Gatineau-bound traffic, according to peak hours.

The replacement of the pedestrian boardwalks took place in fall 2010, while the installation of the inspection walkways underneath the bridge and damping mechanisms to address the vibration of the structure was completed in winter 2011.

The reinstatement of the staging area underneath the bridge was completed in spring 2011.

Feedback and contacts

If you would like more information, please contact PWGSC's Real Property Branch.