Award Nomination
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:
Broadway Subway Project | ACEC-BC Awards (acecbcawards.com)
Project Overview
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.
Project Scope
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
Kudos to the Team!
Project Profile
Read more about the challenges faced by the team and their innovative approaches to facing them here.
