Dufferin Mall

Dufferin Mall Pedestrian Tunnel

This renovation project includes the challenge of constructing a 10ft wide by 12ft deep pedestrian tunnel inside an active mall. HCM together with RWH Engineering proposed an innovative design and construction process to accomplish this endeavor with very limited working space and tricky access issues. The construction involves:

• Shotcrete shoring to allow for vertical excavation of the tunnel area

• Bob Cat mounted TEI drill for the installation of tie backs

• Removal of excavated material via narrow stairwells and utility corridors

• Supply of materials and tools via narrow stairwells and utility corridors

In addition, HCM’s scope of work includes increasing the depth of an existing elevator pit, building underpinning, exterior stair concrete footings and retaining walls.

Client: EllisDon Corporation
Location: Toronto, Ontario

London Mental Health

London Mental Health – Structural Shotcrete

HC Matcon completed a 1,650ft2 structural shotcrete wall in just two days of shooting concrete. The wall had a depth of 0.450m thickness and was (on average) 10m in height.

The first day, Matcon placed a scratch coat at 0.400m thick, and then a surface coat at .050m thick on the second day. Since no form work was used, there was no need for stripping and finishing the wall.

This was the first structural shotcrete wall for both HC Matcon and EllisDon Construction.

Client: EllisDon Construction
Location: London, Ontario

St. Thomas Courthouse

Alternate Methods Stop Running Sands

HCM was retained to design, supply and install a complete shoring system to facilitate construction of the new St. Thomas Court House for EllisDon. Construction of the proposed shoring was initially for soldier piles and lagging with a single level of bracing using tiebacks.

The existing structures were initially designed using conventional underpinning. When excavation reached the underside of the existing structures it had been determined that soils were not what expected in the geotechnical report. The existing soil conditions were flowing wet sands and HCM was asked to provide an alternate method to the conventional underpinning.

HCM implemented a shotcrete underpinning system including positive support of the existing rubble foundation to allow us to support the structure and lateral pressure of the earth while excavation proceeded to base of the new structure.

With the assistance of RWH (an HC Group of companies) our ability to react and provide an alternate design solution allowed HCM to complete successfully the shoring and foundation works within EllisDon’s budget and schedule.

Client: EllisDon Construction
Location: St. Thomas, Ontario

EEEL University of Calgary

Zero Ground Loss

This project followed shortly after finishing the Taylor Family Digital Library project, which was in close proximity to this site on the same campus. Design considerations for the foundations were almost identical to the previous project, with the installation of approximately 175 cast-in-place belled piles. Again, this new building was a result of the fast-growing population at the University of Calgary and the demand for specialty studies with emphasis on future global trends such as clean energy and the environment.

The soil conditions, which are typical and uniform throughout the mentioned site, consisted mainly of silty sand and clay till which is ideal for large capacity belled piles.

The shafts for the piles were predominantly 900mm, 1000mm, and 1,200mm in diameter.
The bells were sized at: 2000mm, 2400mm, 2800mm, 3400mm and 3600mm in diameter.

The average founding depth on this project was approximately 13.0m – 17.0m with the need to protect the upper portion of the pile shafts by using temporary casing approximately 8.0m long. The concrete volumes for single piles ranged between 23 – 26 cubic meters. Among the challenges for HCM on this project was installation of piles in close proximity to a concrete utility tunnel. EllisDon approached HCM with a request for shoring and underpinning on a portion of the tunnel.

HCM proposed a design/build tied-back continuous caisson wall method where special consideration was given to the stated goal of zero ground loss from underneath of the tunnel.

Client: EllisDon Corporation
Location: Calgary, Alberta

Scarborough Hospital

A Design-Build Solution

The Scarborough Hospital was adding a new Critical Care Centre in the courtyard surrounded on all sides by existing hospital structures.

HC Matcon’s scope of work included:

excavation of the new building foundation on pad footings
permanent shotcrete underpinning system to support surrounding structures
soldier pile and lagging wall to support a pedestrian walkway adjacent to pad footings and service manholes
demolition of service tunnels while maintaining operation and maintenance access for emergency services and hydro caissons to support new canopies and additions to existing structures.

At various points during construction, HC Matcon has been required to provide innovative design-build solutions to accommodate changes to the original design.

Client: EllisDon
Location: Scarborough, Ontario

Mars B Toronto General Hospital

This 3.5 Million dollar contract involved HC Matcon providing a full excavation, a 16,000 Sq. Ft. shoring and large diameter caisson package for this project. Challenges included the support of historical facades, tight working room, land locked site location and staged demolition. The site required all 4000 Dump Truck loads to be removed through a narrow laneway. HCM demolished a 14 Ft. brick service tunnel, while maintaining a 6 inch live steam line, through piled supports, eventually digging under the live line to maintain schedule. The combined shoring and excavation package was well suited to this project requirement as tight co operation between the excavator and shoring contractor was critical. HC Matcon maintained excavators on site during the full project duration which allowed for many advantages to Ellis Don and the owner.

Client: EllisDon
Location: Toronto, Ontario