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 mainly involved 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 tons of rock was excavated, crushed, loaded and removed from the site to make way for 1.5 km 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-ton 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-level structure (seven levels 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 mining operation. 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 disposed of. 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 mm thick. It keeps small pieces of rock from falling from the tunnel wall between the excavation and concreting phases.
To improve adherence, 45 kg of steel fibre is 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 Azur trains will one day run.
Construction of this new infrastructure is required to meet four 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 growth in ridership expected in coming years
- Ensure that the offer of service expands to keep pace with the Blue line’s forthcoming extension
Three surface buildings are necessary for this garage’s operation.
The first, three storeys high, will be erected on the part of the land located above the garage. It will give access to the garage and the employees’ workplace.
Two auxiliary structures will also be built. The first, which will be located near the Recreation Centre, will serve as an emergency exit for the personnel. 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 to be built. It will be composed of a yard, located at the garage entrance, that will allow trains to proceed to one of the tunnels in which trains can be accommodated. A lead track will allow train traffic between the Côte-Vertu station and the garage. Finally, a train maintenance pit will be integrated into the garage to perform more efficient interventions on the rolling stock fleet. The depth of the underground garage can be compared to a 10-storey building.
It became necessary to add parking space at that end of the Orange line to maintain a balance between the number of holding spaces at each extremity of the line. That balance will allow us to improve the frequency of service, among other things.
Five trains can currently be parked in the garage behind Montmorency station and 20 others at Henri-Bourassa garage. These recent infrastructures, built when the métro was extended into Laval, have certainly helped to uphold the quality of service. But, on the other hand, no such infrastructure has been added to the west end of the line since 1986.
Ten trains are currently housed in the station tail tracks. The new Côte-Vertu garage can hold an additional ten spaces.
The construction work will last approximately four years.
To reduce the sources of noise coming from the cut-and-cover excavation, anti-noise walls will be constructed at the beginning of the work. They will be constructed near locations where we will perform excavation. Rigorous monitoring of the noise level and the vibrations will allow us to take the appropriate corrective actions.
Blasting generally will be used from Monday to Friday, once a day, at the end of the day.
The other underground components of the garage will be produced by 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 the job site’s neighbours.
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 earth from accumulating. Finally, a truck cleaning area will be developed within the job site.
A trucking plan has been developed to minimize truck traffic on local streets. Heavy vehicles will mainly take Boulevards Thimens, Marcel-Laurin and Côte-Vertu. The development of a traffic lane within the job site will 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 beginning the winter of 2020. We are drawing up an action plan that will allow you to use bus and métro services during this period. The information regarding the closing will be communicated on our website.
To minimize the impacts for the clientele, the closing is scheduled 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 work site 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 to remove all soil material. Trucks will enter the site from boulevard Marcel-Laurin.
Indeed. The possibility of a 2-minute interval between trains during rush hour is foreseeable. Today, that interval stands at 2 minutes and 30 secondes.
Working to obtain an ENVISION award
In line with our commitment to integrate the best sustainability practices into our own, 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 verification 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 fulfills three essential tasks:
• Comfort ventilation: Regulates the indoor tempreature for the comfort of passengers. Trains produce nearly 80% of all heat in the underground network merely by braking and accelerating.
• Night-time ventilation: Ensures a supply of fresh air for workers at night carrying out routine maintenances 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.