Twenty-five metres (82 feet) below Eglinton Avenue West, I suddenly and absurdly thought, "Wow, this is actually happening!"
"This" is the 19-kilometre (11.8-mile) Crosstown Light Rail Transit line, stretching from Mount Dennis on the west side of Toronto to Kennedy in the east. I was standing at what will eventually be track level in the future Keelesdale station.
I write a lot about public transit projects and so, of course, am completely aware of the details of this project: the demolished buildings; the blocked roadways and sidewalks; and the seemingly endless traffic jams. Even though construction has been underway for more than three years, all that street-level work seems, psychologically at least, completely separate from the hive of activity taking place under it, because for most people it's hidden from view. Although I recently visited the mostly outdoor station at Mount Dennis—one stop to the west—the effect of heading underground for the first time was astonishing.
Metrolinx and its contractors, Crosslinx Transit Solutions, invited members of the media to tour the future station to help explain the "cut-and-cover" construction process that Crosslinx is using to build nine of the line's 15 underground stations.
The future station at the intersection of Eglinton with Keele Street and Trethewey Drive will eventually have three street-level structures to allow passengers to enter and exit the station. We first visited the site of the main entrance on the northwest corner of Eglinton and Trethewey to peer down into the excavation toward the station base, where, shortly, we would be standing. Daniel Sanchez, Crosslinx' project manager for the station, acted as our tour guide and led us through two major work areas, describing the process of building the station.
In March 2016, crews started installing permanent station head- and side-walls at the site. First, they built shoring walls around the areas that they intended to excavate. Shoring required the contractors to drive large steel beams called soldier piles deep into the ground at regular intervals along the perimeter of the station, and around the station's entrance buildings. In between each vertical steel beam, lagging—timber slats—was inserted to carry the load. Then, digging commenced, and once they were deep enough to reach the tunnels that had already been constructed, the tunnel liners were removed at each station site.
The shoring walls for station’s excavation pit—about 130 metres long by 20 metres wide (426.5 by 65.6 feet)—were supported by both steel braces or tie-backs drilled into the earth as the pit grew deeper. In total, the crews removed about 80,000 cubic metres or 2,825,173 cubic feet of material from the site.
A problem, Sanchez said, was ensuring traffic could flow along Eglinton and Keele while crews worked under the street. His crews temporarily shifted traffic to the north side of Eglinton and the east side of Keele and Trethewey, while they dug a shallow pit on the other side. They then installed wooden decking above the excavated area so the traffic lanes could then be restored. Next, the process was repeated on the south and west. The decking required 2,300 square metres (24,757 square feet) of wood—enough to cover the floors of five basketball courts.
"This is an interesting project," Sanchez said. "One of the many challenges that made it interesting was the large number of underground utilities at the site, including water-mains and sanitary and storm sewers. He pointed to a large pipe that was suspended high above the pit, stretching from east to west close to street level. He explained that at this site his team couldn't relocate these "wet" utilities, so they carefully dug around them then installed hangers to suspend them from the street deck, allowing them to dig deeper below.
Sanchez then guided us across the street to the site of the tertiary entrance on the southeast corner of Keele and Eglinton. (A secondary entrance stands on the northwest corner beside York Memorial Collegiate Institute.) There we descended about five stories down to the floor of the site, where workers busily laboured while reporters filmed and interviewed Sanchez and other Crosslinx officials further.
Light streamed from the site of the station entrance structures above, simulating the final effect for passengers awaiting trains when construction ends. (All street-level entrances will be mostly glass.) The high ceilings gave the site a cathedral-like atmosphere, with the twin tunnel portals at the east end demanding our visual attention. Orange tarpaulin covered much of the rough concrete floor, which the team had poured just the day before while a non-stop parade of concrete mixer trucks and a series of pumps delivered liquid concrete to the site continuously over eight hours.
Crosslinx expects to substantially finish the station by July 2020, when Metrolinx starts using it as part of a test track for the Bombardier cars. The cars will be prepared for passenger service by first logging 600 hours during short runs between Mount Dennis and Caledonia stations; Caledonia is the next station east of Keelesdale.
When open to passengers, targeted for September 2021, the station will also include a four-bay bus terminal behind the main entrance at Trethewey and Yore Road. (Keelesdale is one of the few Crosstown stations to get such a terminal.) The TTC plans for buses in both directions along the 41 Keele and 941 Keele express routes to stop in the terminal. Local buses along a new route, which the TTC is tentatively designating as 58 Trethewey, will also call there.
Crosslinx is using cut-and-cover to build eight more stations along the line: Caledonia, Fairbank, Forest Hill, Chaplin, Mount Pleasant, Leaside, Laird (part), and Science Centre. It's mining where geology permits—digging out the stations from the shafts at the entrance sites, and working deep beneath the surface with much less impact to the street above—at Oakwood, Avenue Road, and Laird (part). Cedarvale and Eglinton stations require a variety of construction methods because they serve as interchange stations with the TTC's U-shaped Line 1 Yonge - University subway.
UrbanToronto will continue to update you on the Crosstown LRT project as it progresses. What do you think about this station or the line? You can add your thoughts in the space provided on this page, or join the discussion in our dedicated Forum thread.
|Related Companies:||Crosslinx Transit Solutions, Daoust Lestage Architecture, GFL Environmental Inc., IBI Group, LEA Consulting, Metrolinx, NORR Architects, SvN, Toronto Transit Commission|