Associated Engineering provided construction engineering services to Surespan Construction for Phase 2 of the Ross River Bridge Rehabilitation. The pedestrian suspension bridge spans the Pelly River and is approximately 200 metres long. A historic structure, it was constructed in the 1940’s to support a pipeline and later converted to a pedestrian bridge.
Phase 2 included replacement of the vertical hangers and horizontal wind cables; new suspension cable and wind cable anchor foundations; and timber truss superstructure replacement. Associated Engineering provided construction engineering services as well as alternate designs for the main cable anchor block and the wind cable deviator tower and anchorage, resulting in cost and time savings to the project.
Associated Engineering provided alternate design for the foundations of the main suspension cable anchorage. The original system was based on helical screw piles, with steep batter and over 24 metre depth. Despite poor soil conditions, a different arrangement of concrete-filled driven pipe piles was successfully designed. Alternate design for the wind cable deviator tower and anchorage involved a single anchorage system using pipe piles and a steel cap plate. These alternate foundation systems minimized excavation; eliminated the need for excavation below the water table; and allowed construction to continue through the winter. Significant cost and time savings were also achieved through reduced concrete volumes and faster pile installation.