He said the building's location created challenges. “The building footprint is 1,886 sq. m. and sits on a total site area of 9,901 sq. m. The site is bordered on the south and north by residential houses and to the west by Highbury Ave., which is one of London’s main roads.” He says there is a significant change in grade along Highbury Ave., dropping more than seven meters from the high point at the south to the low point at the north. Within the site itself, the major grade difference he said, occurred along a slope running diagonally from the southwest cor- ner to the northeast corner; with the upper elevation up to nine meters above the base. “Due to extensive topographic changes, the available site area consists of an elongated triangular parcel extend- ing east from Highbury Ave. between the bottom of the slope running along the south side of the site and the slope created along the north.” He said because of this, the staging area and parking were very limited. To accommodate parking for the trade contractors a temporary parking lot had to be created at the top of the hill at Jensen Rd. “There was no parking per- mitted on site except for one vehicle from each trade con- tractor firm. Trades were responsible to shuttle manpower and tools to the job site or walk down the hill via the path and temporary stairs created.” In addition “the existing fill, topsoil, peat, marl and soft clay was not suitable to support the proposed building foundations and floor slabs due to the low strength and high organic content in the material,” Nguyen said. To solve this problem and support the building, 308 steel pipe piles, 250 mm in diameter were driven to depths ranging from 4 m to 10 m below the underside of the con- crete grade beam elevation. Once driven to the required depths, Nguyen says these piles were filled with 30mpa concrete. “The last steel pile was driven 2.5 months after the trade contractor mobilized onto site.” He says additionally, due to the decomposition of fill ma- terial and organic matter in the peat and marl deposits, there were methane gas concentrations. “The design of the building foundation included a combination of pile caps and grade beams. The use of this foundation resulted in the area beneath the building being divided into individual cells, which would be isolated from each other and allow for gases to accumulate beneath the structural slab.” Nguyen says it is an honour to win the OGCA award. “It brings satisfaction to Bronnenco knowing that we com- pleted a project that is highly recognized by our peers within the construction industry.” Sewers / Watermains • Roadworks / Parking Lots Excavation / Earthworks • Design / Build Equipment Rentals • Trucking / Snow Plowing Congratulations Bronnenco! 3003 PAGE STREET, LONDON, ONTARIO N5V 4J1 519-652-2104 www.johnaartsgroup.com asantos@j-aar.com The Canadian Design and Construction Report — July-August 2015 – 55