The Stockyards development project consists of the construction of multiple commercial retail units, some with second floor residential space, multi-storey townhouse complexes and a three storey parking garage. The project is located north of St. Claire Avenue West, west of Weston Road and is bound by Gunns Road to the north and west, in the City of Toronto. Residential properties are located close to the project to the north and east. As an alternative to costly large scale excavation and replacement, Menard Canada proposed a value-engineering solution utilizing Dynamic Compaction (DC), Rapid Impact Compaction (RIC), Menard Canada Piers and Controlled Modulus Columns (CMC), to improve the upper 6-15 meters of soil on this challenging project. Soil improvement was necessary to compact the loose heterogeneous fill across the northern area of the site to minimize the potential for total and differential settlements. The total depth of fill varied from 6 to 15 meters, with an average depth of 10 meters to be improved. The objectives of the treatment were to compact the soil in order to obtain a minimum bearing capacity of 150 kPa at SLS, 225 kPa at ULS, with a minimum safety factor of 3 at SLS, and to limit total and differential settlements under the buildings and parking structure to 25 and 15 mm respectively.
Based on Menard Canada’s design, an 8 to 17.5 ton high energy steel tamper was dropped from a maximum height of 16 meters to compact the northern portion of the project in four phases. The RIC machine was used to compact the central portion and perimeter of the site in 6 phases. Menard Canada Piers were installed to a maximum depth of 6 meters and CMCs were installed to a maximum depth of 12 meters at the north-eastern limits of the site. The DC phases were designed to densify the soil to a depth of 15 m, while the RIC phases were designed to densify the upper 6 meters of fill. The craters were filled with crushed concrete upon completion to eliminate the ironing phase. The ground improvement program was completed on schedule, with all tests attaining the intended results. Menard Canada successfully delivered cost effective solution of soil improvement providing a reliable method, appropriate for the project and site conditions.