Jazz Condominium Burlington, Ontario
Prior to 2005, when you had bad fill on your site you either had to “remove it”, or “go through it.” Developers, contractors, and consultants now know that there is another alternative to dig-replace or deep foundations. Today, countless projects throughout Ontario are supported on ground improvement systems, and a great many of them are on undocumented fill, often containing deleterious materials such as debris or organics.
The Jazz condominium, a development by Branthaven Homes, is a mid-rise 4 storey condo in Aldershot, Ontario. With 79 suites ranging from 550 SF to 1300 SF sitting atop a main level commercial retail space and lower parking, this is a key new residential multi-use building in Burlington’s west end.
The pre-existing site was a mini golf course. Many years ago, the site was a river bed, as can be seen from historical aerial photography, and it was filled in over time. The result was a site with up to 6m of undocumented sandy fill in a loose state. Even with the excavation for the basement, up to 4m of fill remained below the parking areas finished floor elevation, and native soils below that were also in a loose state as well.
The ground water level at the project site was at roughly 0.75m to 1.2m below the parking FFE making dig-replace very challenging and essentially impossible to undertake in the sandy fill soils.
The foundations of this structure were subject to column loads of up to 1,200 kN, wall loads of up to 150 kN/m and slab loads of 12 kPa. The settlement criteria for the structure was 1 inch total settlement and ¾ inches differential.
The team required a cost-effective foundation solution that could be installed with minimal delays to tight project schedules. Soil Mat Engineers, the projects geotechnical consultant recommended several options including Rammed Aggregate Piers, which were ultimately chosen over both helical piles and drilled and fully cased caissons. These piling options would have required the design of pile caps, grade beams and a full structural slab.
The improved bearing capacity provided for standard spread footings by the Geopier Impact system was 260 kPa at Serviceability Limit States (SLS) and 360 kPa at Ultimate Limit States (ULS). A standard, thin, unreinforced slab on grade was supported by additional Geopier elements.
Installation of the Geopier elements was conducted quickly from existing grade which was then cut down later. This work was completed prior to obtaining foundation permits, providing a real boost to the project’s schedule. Full-time quality control was provided by GeoSolv’s construction team and the Geopier capacities were verified in the field by a full-scale load test which demonstrated less than 12 mm of deflection at the maximum design load.
The Geopier construction for “The Jazz” was completed in about 5 weeks. The completed Jazz condo, which sold out quickly, is a key piece in Burlington’s intensification plans. The use of Geopier Ground Reinforcement on this project is clear proof that, when faced with poor fill soils, you now have three options, “remove it”, “go through it”, or “IMPROVE IT!”
Additional information on the Geopier Impact System used for this project can be found here: