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Oxford Airport Business Park

Oxford Airport Business Park
Date: 2015

General Contractor Ledcor Construction Ltd. contracted AGRA Foundations Limited for the pile foundations of three large warehouses to be built in close proximity to the Calgary Airport. Each warehouse was approximately 240 m long and 92 m wide, with a footprint of 240,000 square feet.

Ground conditions on site consisted of fill above clayey silt/ clayey sand overlaying bedrock. Rock depths varied from 6 to 18 m across the site. The bedrock was weathered, interbedded siltstone, sandstone, and shale.

Piled foundations were to support the external structure and the internal columns of the warehouse. AGRA designed the piled solution. The foundations for two of the warehouses were constructed using Continuous Flight Auger (CFA) piles, and a third warehouse is supported by belled cast-in-place piles.

Solution:

AGRA provided a design build solution for the piled foundation. Two test piles, one CFA and one belled, were completed in advance of the works to optimize the design. Ground conditions were variable across the site and below warehouse I the silt was clayey and stiff enough to use a belled pile.

On buildings G and H the sand and gravel content in the silt was much higher and the ground sloughed in. CFA proved to be a quick and efficient method that did not require casing to support the ground. AGRA used two of their heavy duty CFA rigs which easily drilled through the weathered rock.