2023 #CCEAwards Showcase: Vendôme Station Entryway and Pedestrian Link

Photo ©Julien Perron-Gagné, courtesy AtkinsRéalis.

Category: Transportation

Award of Excellence Winner: AtkinsRéalis

The Vendôme intermodal hub project stemmed from the Société de Transport de Montréal’s (STM’s) universal accessibility policy, which provided a mandate to connect the metro station with an Exo train station and the McGill University Health Centre (MUHC). As a result of this project, the Vendôme station is now certified Envision Gold—making it the first STM metro station to obtain such distinction.

The project originated when STM announced plans in 2015 to build a second entrance building for one of its busiest intermodal stations, to make it accessible to people with reduced mobility. This would also involve adding tunnel connections to Exo’s station and the MUHC. AtkinsRéalis (when it was still SNC-Lavalin) would provide multidisciplinary engineering—including structural, civil, mechanical, electrical, automation, acoustical and vibration, air quality, traffic and urban engineering—and human health and ecological risk assessments.

Prior to the renovation, travel between the hospital and the station was a challenge, due to poor accessibility and safety issues. Today, the station is equipped with five elevators, enlarged motorized doors and swing gates that meet the highest standards of universal accessibility and provide a well-flowing link between the station and the hospital, thus improving the travelling experience for all users, but especially for those with reduced mobility.

In addition to improving accessibility, the project has improved evacuation and response time for the station in emergency situations, prioritized intermodality and pedestrian traffic flow to improve travel times and improved capacity to accommodate increased ridership.

A first-in-Canada technique

To limit train service disruptions, AtkinsRéalis’ engineers took a different approach to constructability. A 12-m long, 9-m wide, 650-t concrete tunnel would be slid into place. The bottom slab of the tunnel was designed with a tapered geometry toward the front, resembling the tip of a ski, thus facilitating the sliding of the tunnel on the ground to its final position.

This specific sliding technique, developed by Freyssinet, is called Autoripage and was a first in Canada. The reinforced concrete tunnel was prefabricated directly on-site, next to its final location, and was designed by AtkinsRéalis’ team for the loads induced by the chosen construction technique and then pushed into place by computer-assisted hydraulic jacks. This operation was completed in less than 60 hours.

Due to a lack of space on the adjacent MUHC grounds (vehicle and ambulance traffic), poor soil capacity and time constraints (another 72 hours), the team designed the tunnel under the existing third track in four prefabricated sections, to be assembled on a steel beam mattress filled with grout to limit differential settlements.

Prior to the construction phase, the design team met specialized contractors after a call of interest, to collect risk management information regarding the challenging procedures and to validate the availability of skilled labour for the targeted period. This helped develop the 72-hour construction sequences in nine major steps. These detailed sequences would be the starting point for the main contractor’s schedule.

The project has added tunnel connections to adjacent buildings for greater accessibility. Photo courtesy AtkinsRéalis.

Satisfying stakeholders

The project involved many stakeholders in one of Montreal’s oldest and most densely populated neighbourhoods, all converging at the Vendôme intermodal station. These included STM, the provincial ministry of transportation (which provided financing), Exo (as commuter train operator), MUHC and an adjacent building at 5100 de Maisonneuve W. (as a new entrance would be partly integrated in its ground floor). The project’s complexity lay primarily in respecting all of their requirements.

By way of example, the design team detailed a vibration monitoring program for the main contractor before and during the construction period, to avoid any impact on the stakeholders’ nearby operations.

In addition to stakeholder specifications, the new structures within the Canadian Pacific (CP) right-of-way had to be designed in compliance with CP’s standards and approved by its structural team. In further consideration of a future fourth track, AtkinsRéalis designed a 900-mm thick, 6-m high and 37-m long crash wall, thus protecting commuters in the new entrance building in case of derailment.

To support the local economy and reduce long-distance transportation, 40% of materials (by cost) were regionally sourced. More than 1,100 jobs were created during design and construction. Once the station is fully operational, eight employees will be working at the facility.

Earning Envision

To further support the client’s approach to use by-products, gain experience for future projects and earn environmental points for Envision certification, AtkinsRéalis partnered with the research chair of Sherbrooke University and the City of Montreal in specifying concrete containing recycled glass powder for the totality of a new bus loop’s pavement.

Other infrastructure elements used 50% limestone cement, for 50% less carbon dioxide (CO₂) emissions than a typical mix. Further measures that helped obtain Envision certification included recycling more than 75% of construction residues, managing contaminated soil, integrating a green roof and preventing pollution during construction.

Considering the impacts of climate change is also a key element of Envision. The civil engineering team ‘oversized’ the stormwater management design to help resist the heavier rainfall of a 100-year frequency stormwater event.

“This recognition reaffirms our commitment to sustainable development and our teams’ expertise in implementing innovative solutions for major projects that benefit neighbouring communities,” said STM board chair Eric Alan Caldwell upon the project’s successful Envision certification. “Truly, everybody wins.”

Vendôme Station Entryway and Link, Montreal, Que.

Award-winning firm (prime engineering consultant): AtkinsRéalis, Montreal, Que. (Justine Mainguy, P. Eng.; Julien Doyon-Barbant, P.Eng.; Nikolay Kotchev, P. Eng.; Sébastien Berger, P. Eng.; Ivan Pramatarov, P. Eng.; Zilmara Volpe Grote, Tech.; Vincent Maffolini, P. Eng.; Audrey Cloutier Drouin, P. Eng.; Marc-Antoine Roberge, P. Eng.; Sylvain Lachance, P.Eng.).

Owner: Société de transport de Montréal (STM).

Other key players: MUHC (client), Exo/Réseau de transport métropolitain (client), Bisson Fortin (architect), Provencher Roy (architect), CRT Construction (general contractor), Freyssinet (specialized subcontractor), Research chair of Sherbrooke University (expertise for integration of glass powder in concrete), Groupe ABS (materials and geotechnical engineering), Lafarge (concrete supplier), Tricentris (glass powder supplier), Béton Préfabriqué du Québec (BPQ) (tunnel prefabricator), Substructur expert-conseil (soldier piles and lagging walls), Preco-MSE (soldier piles and lagging walls).