Viau Station - Redevelopment of An Underground Workshop

Being mostly experienced with large residential, commercial and institutional projects, Magil took upon a great challenge with this infrastructural public contract. Constructed in the 1976, the station also includes a large lobby above ground and a tunnel garage for the maintenance of way equipment. This multidisciplinary project included both an architectural portion (the upgrade and renewal of the large station pavilion and ticket hall with the addition of two elevators) and a civil and infrastructural portion (the new maintenance tunnel and the renewal of the existing one).

The complexity of the work sequence and of the site logistic paired with the inherited risks of a public lumpsum contract, worsened by the conjuncture which our industry has been going through recently. Some of the challenges included:

• complex site logistic, due to the intermodal nature of the station, which was fully operating while the construction progressed
• difficult MEP coordination between existing systems and new installations
• a tight schedule, high quality standard and the aforementioned lack of any 3D model of the existing structure and of the future project.
• higher prices for some elements, like the special precast finishing groove panels
• the lack of available specialty contractors, which led to higher cost and even to Magil having to self perform some of the works

To overcome these challenges, Magil proposed a comprehensive approach, combining reliable experience and expertise with the latest technological tools to facilitate the project’s cost effectiveness and ensure success across all disciplines.

Magil adopted a "Scan-to-BIM" approach: the point-cloud constituted the base to the in-house BIM model of the project and was shared with the MEP trades, who completed it with their models, allowing for a highly efficient coordination process. Magil also modelled the design modifications issued by the design team, to validate their constructability.

During the construction phase, fully integrated and mobile CDE platforms were adopted. Mobile tablets integrated with the CDE were deployed for the construction team, and made the federated model accessible from the field, for improved work monitoring and quality controls.

The train clarence zones were modelled and superposed with the laserscan survey at the end of the construction. Magil used virtual reality, to quickly check compliance.

The lidar device was also used to document the location of mechanical ducts and rebar in the slabs, knowing that several anchors would have been necessary for the installation of mechanical equipment. This made possible to drill hundreds of anchors without damaging any pipes or rebars.

A micro-drone has been used throughout different phases to document in detail the progress of the work and the state of the site, improving communication between all project stakeholders.

The different phases of the site logistic were modeled and kept up-to-date. Being the train station fully operating, and the site in the middle of a very busy area, this helped to accelerate the validation process from the client, as well as the training time needed to let new workers and subcontractors in.