The transformation continues
The future underground métro train garage is taking shape! The concrete work is nearly done, leaving only the immense 50-metre-wide hole for the fan of tracks that workers began digging out as soon as the worksite opened. The fan is now the main access point to this vast underground worksite. Until very recently, concrete mixers could be seen driving down a massive access ramp to the very bottom of the site, where they poured out the thousands of cubic metres of concrete required to build the tunnels.
Today, a cathedral of reinforcements and forms occupies the space as the fan takes shape, being poured in concrete. The fan is essentially a cluster of tracks branching out so that trains coming from the Côte-Vertu tail tracks can turn around to face the appropriate tunnel in the garage. Once the concrete work is complete, the fan will be fully enclosed underground.
Tunnel track installation has begun
While the concrete work nears completion, a specialized team is working to install the tracks in the tunnel. Specifically, the elevated tracks in the maintenance tunnel are now fully installed. This system of raised tracks provides a much more ergonomic work environment for mechanics when they conduct maintenance on the métro trains.
Over the next year, a number of teams will work on installing tracks in the connecting tunnel and the fan. Along with the built-in electrical system, these new tracks will allow us to manoeuvre our Azur trains efficiently within this imposing structure.
Work is also underway on the site’s architecture, mechanical and electrical infrastructure, fire prevention, lighting and ventilation.
The site of the future Côte-Vertu underground métro train garage is one of the largest worksites in the city, involving a number of trades and several hundred people working there every day.
The future underground métro garage in images
The maintenance shop is located more than seven stories underground, in the tunnel where maintenance work on rolling stock is conducted
The immense 50-metre-wide hole for the fan of tracks is the main access point to this vast underground worksite
A cathedral of reinforcements and forms occupies the space as the fan takes shape, being poured in concrete.
The installation of tracks on blocks is underway in the second tunnel
We can currently park 25 trains on the east side of the Orange line at garages at Henri-Bourassa and Montmorency stations, but the west side has only 10 parking spaces at Côte-Vertu station. The new garage will add another 10 parking spaces and balance capacity at both ends of the Orange line. That will allow us to support expected growth in ridership over the coming years and increase the offer of service to keep pace with the extension of the Blue line.
Concrete work is currently under way in the fan of tracks that allows trains to access the right tunnel. The fan will eventually be fully enclosed underground by a concrete structure.
We can already imagine the rails that will guide trains from the fan towards this enclosed parking tunnel.
Installation of the fire protection system is under way in the parking tunnels.
Concrete work continues in the connecting tunnel. After the invert is poured, travelling forms are installed so the tunnel walls and vault can be poured.
Three surface buildings will be built as part of project. Two auxiliary structures will be used: one to provide an emergency exit for employees and one to provide access to a mechanical ventilation station. The third building will provide access to the underground garage and train maintenance shop. The picture above shows how work is progressing at the shop, where our new Azur trains will be inspected and maintained.
An 875-kilogram track bumper is being installed at the end of the pit to ensure optimum parking for the train to be maintained.
Complex cabling is being installed to supply electricity for the various components needed for train maintenance and garage operations.
The maintenance pit can handle a nine-car Azur train.
A team is installing mechanical components to provide optimum ventilation in the maintenance shop.
Check out the worksite highlights below!
All precautions are taken to ensure workers’ safety, including an impressive ventilation system to ensure air quality in the underground tunnels.
This 135-tonne machine, called a roadheader, was used to crush the rock and dig the tunnels. This mechanical excavation method replaces blasting and therefore reduces vibrations and nuisances for neighbouring residents.
A project of this size requires meticulous surveying work.
Certain sections of the project include an open pit. Here, we see the future site of the 10-storey structure (seven storeys will be underground), which will provide access to the AZUR train maintenance workshop.
Sprayed concrete is reinforced with small steel fibres and holds the rock in place between the excavation and concrete work phases.
A specialized team installs the reinforcing steel.
Numerous anchor points reinforce the steel structure on the rock.
A blinding slab must first be poured to enable the travelling form to be installed, which allows concrete work to be performed on the vaulted ceiling.
The travelling form is then assembled and used to mould the form of the tunnel so the concrete can be poured.
Excavation of the new tunnel linking the underground garage to the Côte-Vertu station is in full swing! Our teams are working around the clock to build this 600-metre tunnel, 25 metres below street level. By the end of the digging, we will have excavated the equivalent of 14 Olympic swimming pools of rock!
The worksite is like a mine site. All precautions are taken to ensure workers’ safety. Among other measures, the names of the workers on the site are posted at the tunnel entrances.
The roadheader literally crushes the rock, which is then loaded and removed. In technical jargon, this is called “mucking.”
The roadheader has a total of 240 teeth (120 per head).
To ensure equal wear, the teeth are rotated.
Depending on wear, an average of 10 to 30 teeth are changed each day.
The sprayed concrete is 50 millimetres thick. It keeps small pieces of rock from falling from the tunnel wall between the excavation and concreting phases.
To improve adherence, 45 kilograms of steel fibre are added per cubic metre of sprayed concrete. Seen close up, the sprayed concrete wall has thousands of small metallic “hairs.”
Consolidation bolts prevent large chunks of rock from falling.
The artificial cave created by the workers is starting to look more and more like a tunnel where the Azur trains will one day run.
The new infrastructure will meet four main objectives:
- Add track space for parking trains
- Increase passenger capacity by improving frequency of service and by adding more trains on the Orange line during peak period
- Handle the increase in ridership expected in coming years
- Ensure that the offer of service increases to keep pace with the Blue line’s extension
Three surface buildings are necessary for the garage's operations.
The first, three storeys high, will be built on the area above the garage. It will give access to the garage and the employees’ workspace.
Two auxiliary structures will also be built. The first, which will be located near the recreation centre, will serve as an emergency exit for employees. The second, located near the Super C supermarket, will allow access to a mechanical ventilation station and will also be used as an emergency exit.
The underground garage is the most imposing infrastructure that will be built. It will have a yard, located at the garage entrance, that will allow trains to access the tunnels where they can be parked. A connecting track will allow the trains to go between Côte-Vertu station and the garage. Finally, a train maintenance pit will be integrated into the garage to increase efficiency of rolling stock maintenance. The underground garage will be as deep as a 10-storey building.
We needed to add parking spaces at that end of the Orange line to balance out the number of spaces at each end of the line. This will allow us to improve the frequency of service, among other things.
Currently, five trains can be parked on the tail tracks behind Montmorency station and 20 others at the Henri-Bourassa garage. These recent infrastructures, built when the métro was extended into Laval, have certainly helped to maintain service quality. But, no infrastructure has been added to the west end of the line since 1986.
Ten trains are currently parked on Côte-Vertu's tail tracks. The new Côte-Vertu garage will provide an additional ten spaces.
To reduce the noise coming from the cut-and-cover excavation, anti-noise walls will be constructed at the beginning of the work. They will be built near areas where we will perform excavation work. Rigorous monitoring of noise levels and vibrations will allow us to take the appropriate corrective actions.
Blasting generally will be performed from Monday to Friday, once a day, at the end of the day.
The other underground components of the garage will be built using a mechanical tunnel excavation method, which consists of working with a machine called a cutter. This allows efficient excavation of the rock and reduces vibrations. By using this method, we replace excavation by blasting. Since the excavation is underground, it will be performed over a longer period during the week, but without causing nuisances for local residents.
The job site will be watered in a timely manner, particularly during dryer periods, and will mitigate dust release. The streets adjacent to the job site will also be cleaned to prevent dirt from accumulating. Finally, a truck cleaning area will be created within the job site.
A plan has been developed to minimize truck traffic on local streets. Heavy vehicles will mainly take Thimens, Marcel-Laurin and Côte-Vertu boulevards. Building a traffic lane on the worksite will also eliminate on-street traffic.
We must add a switch in the forebay cavern, which will allow trains to be routed straight to the departure platform. This addition will allow us to put trains into service faster. To minimize the impact on customers, we have scheduled to close the station during the summer, as this is one of the least busy periods of the year.
Due to the situation with COVID-19, which caused the temporary closure of construction sites, we have decided to postpone until summer 2021 the closure of Côte-Vertu station. An action plan allowing you to use bus and métro services during the closure will be created. Information will be communicated in early 2021. The postponement should have minimal impact to the project’s overall budget or schedule.
No. The worksite will be located on empty lots that were bought by the STM. The trench excavation site will include a temporary access ramp that will extend all the way down to the bottom of the excavation pit for earth removal. Trucks will enter the site from Marcel-Laurin Boulevard.
Yes. The possibility of a 2-minute interval between trains during rush hour is foreseeable. Today, that interval stands at 2 minutes and 30 seconds.
Pursuing Envision sustainability verification
In line with our commitment to integrating sustainability best practices, we are pursuing Envision verification for this project. The Envision reference framework was developed to cover all the sustainable development aspects of an infrastructure project and each phase of its life cycle (planning, design, construction, operations and maintenance, and end-of-life). It is the top sustainable development tool in North America for major infrastructure projects such as metro and streetcar systems.
Verifying the project will allow us to:
- Consult and involve stakeholders
- Mitigate construction impacts on our community and environment
- Reduce the impacts of materials used (resource consumption and manufacturing emissions)
- Rehabilitate contaminated land
- Reduce operational impacts (residual materials, water and energy savings, noise and vibration reduction, etc.)
- Improve vegetation cover
- Improve the project’s resilience to climate change
To learn more, visit the Institute for Sustainable Infrastructure Website.
A mechanical ventilation station performs three essential tasks:
• Comfort ventilation: Regulates indoor temperature for passenger comfort. Trains produce nearly 80% of all heat in the underground network just by braking and accelerating.
• Night-time ventilation: Ensures a supply of fresh air for workers at night carrying out routine maintenance tasks. These workers use diesel engine vehicles to move along the tracks as the power supply is cut off at night.
• Emergency ventilation: Used for smoke control. Provides a safe evacuation route for transit users and a safe access route for firefighters, should an incident occur.
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This project was made possible by funding from the governments of Canada and Quebec through the implementation of the Public Transit Infrastructure Fund.