Bon Accord

Project Description

A new pedestrian bridge was planned to cross Bon Accord Creek in Surrey, BC. The bridge was a composite steel and concrete design supported by two end abutments and two piers. The two piers were concrete pile caps on the embankment on either side of the creek. Each pier was supported by 8-ea micropiles to carry vertical loads, and 6-ea tieback anchors to carry lateral loads. Both micropiles and anchors were threaded rod in 8”-dia steel casing. The biggest difficulty on this job was access, specifically while working on a steep slope to install the 8” casing through the relatively hard till. SWC accomplished the anchor installation by using two different excavator mounted drills. The first was used to install the casing, while the second was used to install the threaded rod inside the casing. Difficulty with dense soils containing cobbles and boulders slowed production, and several changes to the drilling methods were required. In the end, all the soil anchors were installed with successful load tests to allow for construction of the bridge.