The Giusti Group, Calgary, constructed concrete foundations, columns, and floors for a six-story concrete and steel condominium project in Kelowna, B.C. The 285-unit project was developed and marketed by Cove Properties Ltd. under the name Playa del Sol. “The Giusti Group has provided prompt, professional, and outstanding service to our company for many years,” said Grant Klapstein, president of Cove Properties Ltd.. “Giusti's attention to maximizing efficiency through the use of state-of-the-art equipment and form-work has been exemplary.”
The building site was geotechnically complex for two reasons: the danger of liquefaction under seismic conditions and settlement under static loads. “To eliminate the possibility of liquefaction, we used vibral compaction and sand columns,” said Randy Hillaby, geotechnical engineer with Levelton. “And we preloaded the site to prevent static settlement.” Since the site was close to Kelowna Lake, with its high water table, dewatering was required to keep the excavation open and relatively dry.
The remediated soils could only support loads of 2000 pounds per square foot, so large footing pads were required to transfer the loads of the building into the ground. “Our largest pad measured over 15 feet square with a depth of 30 inches,” said Brian Tomecek, Structural Engineer with TRL & Associates Ltd. “The typical steel configuration was 25- to 30-mm-diameter bars (#8 or #9) at 300 mm (12 inches) on center.” The irregular building site made form layout very difficult. “We decided right from the get-go to use a robotic total station,” said project manager Scott Saunders. “Laying out 270 pads on different angles using strings would have been a nightmare. With the station, one man does the layout—a huge labor saving!”
Precut 2x10s were sized for the required pad dimensions and hinged at each corner for fast installation and stripping. Three 2x4 stakes were driven along each 2x10 and a laser used to locate the exact height. Giusti's workers used 62-inch-wide Fastfoot fabric forming to form the deeper pads. “It is essential to provide adequate slack in the fabric,” said Scott. “Otherwise there will be too much downward pressure, leading to form failure.”
