Underneath the bustling intersection of Keele Street and Eglinton Avenue West in Toronto, construction of the first station for the Eglinton Crosstown light rail transit (LRT) project is just as busy deep below the surface.
The underground Keelesdale Station consists of a 20-metre-by-30-metre main entrance and a station box, which includes the platform and concourse levels, measuring 130 metres long, 25 metres deep and 20 metres wide.
The station was built using a unique cut and cover method, where excavation work is able to continue underneath while traffic flows above on 2,300 square metres of wooden decking that was installed to cover the construction site, explained Daniel Sanchez, a project manager at Keelesdale with Crosslinx Transit Solutions (CTS), the consortium tasked with building the $5.3-billion Crosstown project.
“Some of the particularities and challenges of this station is that we needed to maintain traffic at all times,” said Sanchez. “We had to build this temporary wooden deck over a steel structure to allow the traffic to flow.”
The team shifted the traffic onto one side of Eglinton Avenue West and built all the perimeter walls needed to support the excavation. They then built the temporary deck and flipped the traffic onto the deck.
“We first built a perimeter wall and then we executed the excavation progressively down by levels until the bottom of the pit. Then we created the room to house the future building and we started building up with concrete walls,” said Sanchez, adding about 80,000 cubic metres has been excavated for the station.
“We have now the inverted slab, we are working on the walls, we are working our way up to the roof and from there we just do the restoration of utilities and backfill on top to the final grade.”
The next two years will focus on the permanent structure, all the finishes, mechanical and electrical work, Sanchez said.
“Keelesdale Station was the pilot station,” he noted. “We started in 2016 breaking ground in March and the substantial completion for this station is summer 2020, a year before the substantial completion of the Crosstown LRT project, which is in September 2021. That is because we will be testing the vehicles before the opening of the line.”
In addition to traffic challenges, the team also ran into issues with utilities at the intersection of Keele Street and Eglinton Avenue West during excavation — including watermain, sanitary and storm sewers.
“There was no possibility to relocate them because of the size, the schedule and there is no room to put them,” said Sanchez. “When we were proceeding with our excavation, we had to do first a shallow excavation around those utilities, and then we were hanging them in place, supporting them and then we could dig down.”
Another obstacle was the area’s high water table, he noted.
“Due to the water table in this particular location we have a dewatering system around the perimeter of the wall that allows the water to come out,” he said. “The access is very challenging as well because it’s not a typical cut and cover station that you have a tower just to access for hoisting. Here it’s more difficult and challenging because the accesses are on the side.”
The Keelesdale Station will feature three entrances: the main, fully accessible entrance at the northeast corner of Eglinton Avenue West and Trethewey Drive; a secondary one at the northwest corner of Eglinton and Trethewey, adjacent to York Memorial Collegiate Institute; and a third at the southeast corner of Eglinton Avenue West and Keele Street.
The station will also include an off-street bus loop with four bus bays to serve TTC buses; on-street connections to TTC buses; a station plaza at all three entrances; a landscaped public space outside of a station entrance; and 60 outdoor bicycle parking spaces.
In 2015, Metrolinx and Infrastructure Ontario awarded the contract for the Eglinton Crosstown LRT to the CTS consortium, comprised of ACS-Dragados, Aecon, EllisDon and SNC-Lavalin. The transit system consists of 25 stations and stops between Weston Road and Kennedy Station along Eglinton Avenue West. The line will link 54 bus routes, three interchange subway stations and GO Transit.
CTS will maintain the line for 30 years following completion. It is the largest project to date financed by Infrastructure Ontario’s Alternative Financing and Procurement model.