BAUER Foundations Canada Inc. was contracted by Flatiron Constructors Canada Ltd. to construct 334 foundation piles for Delayed Coker Unit Expansion (DCU). Part of Bauer’s project scope was designing, installing and dismantling two static compression tests for two production piles. The project is located at Canadian Natural Resources Ltd. Horizon site, approximately 75 km north of Fort McMurray. BAUER BG 28 and BAUER BG 18 rotary piling rigs were used to install the bored piles.
Soil profile consisted of, in descending order, glacial deposits that include 3m to 6m sand overlying 3m to 6m of clay and clay till. The till layer is underlain by clay shale of the Clearwater formation with thickness ranging between 5m to 14m.
Piles were three sizes, 620mm, 750mm and 880mm in diameters. They varied in depth from 12 m to 25 m. Piles were designed as friction piles with 2m to 3m embedment in the oil sand. All piles were partially cased to an average depth of 9m to 15m below pile cut-off level. Piles were mostly dry and poured by free fall using a centering chute. Seepage was encountered in 18 piles and concrete was poured using a full length tremie. Due to the variable depth where the McMurray formation was contacted across the site, rebar cages were fabricated longer than required. Cages had to be cut on site to fit the actual drilled depth.
BFCA had to work close to an operating plant with live underground utilities within the piling locations, some of which had not been defined. The work area was congested. There were some delays due to platform availability and readiness.
Despite the challenges, the project was completed safely, on schedule, within specifications and quality targets.