We are pleased to have been nominated for ACEC-BC's 2023 Award for Engineering Excellence for our engagement with the Broadway Subway Project. The Association of Consulting Engineering Companies BC's awards recognize and celebrate technical excellence in consulting engineering services in British Columbia.
The 2023 ACEC-BC awards will take place on April 13th in Vancouver, BC. To read more about the nomination, click here:
The Broadway Subway Project is a 5.7 km extension of the Millennium Line, a route on Metro Vancouver’s SkyTrain rapid transit rail system. The extension will run from the VCC-Clark Station to Broadway and Arbutus Street and replace part of the 99 B-Line bus route. The project includes the construction of six stations, five of which are on Broadway. The tunnel for the line will be constructed using a Tunnel Boring Machine, while the stations and underground structures are being built in open excavations.
Given the project’s need for rail alignment, construction of the stations requires excavation beneath active lanes of traffic. This necessitates the installation of temporary traffic decks as bridges for traffic over the worksites. Allnorth developed a novel design which allows for installation without halting traffic, while supporting both vertical traffic loads and horizontal soil pressures on station excavation.
Allnorth has been engaged as the Structural Engineer of Record for these required traffic decks and developed the following in conjunction with the general contractor:
Temporary bridges for five stations on Broadway
Support of excavation structure (for Broadway-City Hall, Oak-VGH and South Granville Stations)
Utility supports under the bridge for all stations
Pedestrian sidewalks adjacent to and on the bridge
Conducting onsite engineering and inspections to confirm structure release to traffic
Novel Approaches to Complex Challenges
This project has been exceptionally complicated as it takes place in an extremely busy area of Vancouver. As a result, there were continuous challenges necessitating ongoing problem solving and the application of out-of-the-box solutions. Several sophisticated innovative approaches were developed such as a novel and unique construction sequence solution that resolved the continuous traffic flow problem which dramatically reduced the construction schedule. In addition, the following specialty solutions were being applied to the structure:
Bolted splices on the main beam allowing for modularization and easy transportation
Non-bolted connections between the girder and deck
Adjustable non-bolted connections for quick girder installation on steel driven piles
Supporting Broadway’s massive utility infrastructure underside the decks
Project Fun Facts
7,740 engineering design hours
8,500 engineering design hours for construction support
16,000 square meters of traffic deck area
20,000 tons of steel was fabricated for this purpose - equivalent to four Walterdale bridges or one Lions Gate Bridge
With locations across Canada and in the US, Allnorth prides itself on being responsive to client needs and to providing leading-edge methodologies, technologies and protocols. Having a local presence helps us build strong relationships, and working cross functionally throughout the company helps us leverage the strengths of our entire team to deliver successful client solutions. Contact us today for more information as to how we can work together for you.