A busy year for the Côte-Vertu garage project team!
During 2018, we completed several phases in the construction of the Côte-Vertu garage. The work excavation activities, which included boring underground tunnels and pits, installing consolidation bolts and applying sprayed concrete to reinforce the structure.
In 2018, more than 630,000 tonnes of rock were excavated, crushed, loaded and removed from the site to make way for 1.5 kilomtres of underground tunnels. We also finished excavating three open pits where the auxiliary structures with surface facilities will be built.
Did you know?
The stone excavated from the Côte-Vertu garage site was used to build the approaches to the new Samuel De Champlain Bridge.
A project of this size requires careful and complex coordination between the various trades and activities on the worksite. While excavation work occupied 2018, concrete work will fill the agenda in 2019. Specialized teams are busy installing reinforcing steel and travelling forms.
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 forthcoming 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.
This step will eventually require the temporary closing of Côte-Vertu station in the summer of 2020. We will also take the opportunity to do major repairs in the station starting winter 2020. We are drawing up an action plan that will allow customers to use bus and métro services during this period. The information regarding the closure will be communicated on our website.
To minimize the impact on customers, we have scheduled to close the station during during the summer. This is one of the least busy periods of the year. We will keep you informed of the solutions put in place to transport you by bus and métro. The addition of elevators in Du Collège station will ensure easier access to the métro.
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.
Working to obtain an ENVISION award
In line with our commitment to integrate the best sustainability practices, we are working toward obtaining an ENVISION award for this project. While LEED certification is relevant to above-ground buildings, it does not apply to infrastructure projects. The ENVISION certification was developed specifically for unconventional infrastructure projects, such as the métro. Other public transit authorities in Portland and Boston use it as their reference while, closer to home, designers and engineers for the new bridge spanning the St. Lawrence River are also aiming to obtain this award.
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.