94 Cumberland Street

Toronto, Ontario

PROJECT SERVICES

Demolition

PROJECT CATEGORY

Commercial / Residential

PROJECT DATE

April 2020 – August 2022

CLIENT NAME

94 Cumberland Street

The project

The proximity of the project to streets, sidewalks, and other buildings, as well as the restrictive workspace, required a state-of-the-art approach to ensure public safety and the integrity of adjacent structures.

A tower crane was used to facilitate the demolition work so that the building could be lowered on a level-by-level basis to an elevation that would permit the balance of the structure to be safely demolished by machines working from ground level. Small demolition equipment was utilized during the lowering process to systematically demolish and remove the concrete slabs, while the crane was used for lowering the beams, columns, and precast wall panels to ground level.

Covered walkways were erected for public protection along sidewalks adjacent to the site, while mast-climber platforms were installed around the perimeter of the building, not only to provide worker access but also to contain dust and debris during demolition activities.

Delsan-AIM was awarded a contract with The Minto Group to undertake the decommissioning and complete demolition of a commercial office building located in Toronto, Ontario, in the heart of the busy downtown district of Yorkville.

The building, constructed in the late 1960s, consisted of a nine-storey reinforced concrete structure with a footprint of 10,530 ft2, and included a mechanical penthouse as well as a two-level basement. The curtain wall was composed of precast panels and glazing.

Initially, Delsan-AIM completed the abatement of hazardous materials, such as asbestos, which was followed by the removal of interior architectural finishes as well as mechanical and electrical equipment using small machines such as mini-excavators and skid-steer loaders.

The same equipment was then used to create a shaft opening within the building footprint through the structural slabs, from the roof to the lower basement level in accordance with an engineered procedure, which included the installation of high load bearing capacity post shores to maintain the integrity of the adjacent floor structures.

The mast of the tower crane was then erected within the shaft on a new cast-in-place concrete foundation and equipped with a luffing jib above the roof level.

Once the building was lowered to a safe elevation, the remaining floors were demolished using full-sized excavators equipped with specialized attachments, such as concrete shears, hydraulic hammers, and a 75-ft. high-reach boom.

Upon completion of the superstructure, the foundations were systematically removed in a sequenced manner and backfilled with shale in accordance with a detailed engineered design to ensure the integrity of adjoining structures and infrastructures.

The structural integrity of an adjacent occupied building as well as an underground utility vault was critical during the demolition of approximately 140 ft. of the foundation wall. This work required the sequenced and staged removal of the foundation wall along with the installation of concrete, which was cast-in-place below-grade to form a stabilization block that was 8 ft. thick and up to 14 ft. high.