BAUER Foundations Canada Inc. was contracted by PCL Construction to construct 29 foundation piles for three pedestrian bridges over the Elbow River in Calgary, Alberta. The new pedestrian bridges replaced bridges that were severely damaged during the floods in June 2013.

The bridges are located in the neighbourhoods of Rideau, Elbow Park, and Sandy Beach in southwest Calgary. A BAUER BG 18 H drilling rig was used to install the bored piles. The soil profile for Rideau and Elbow Park consisted of gravel from 0 m to 4 m, underlain by clay from 4 m to 20 m and bedrock below 20 m. The soil at Sandy Beach consisted of 0 m to 5 m of gravel, underlain by bedrock.

All piles were 780 mm in diameter and drilled up to a depth of 21 m. Piles were designed as friction and end bearing piles with 1 m to 6 m embedment into bedrock. All piles were partially cased with temporary casing 880 mm in diameter. Seepage was encountered in 17 piles, requiring the use of tremie pipes to place concrete below water. The other 12 piles were dry and were concreted by free-fall using a centering chute. Reinforcing cages were cut on site to fi t the actual drilled depth.

Pile installation at six different bridge abutment locations presented transportchallenges for equipment, tools and casing transportation within the city. Despite the challenges, the project was completed safely, on schedule and within specifications and quality targets.