SH20 Mt Roskill Extension project

SH20 Mount Roskill Extension is a key part of the new Western Ring Route around Auckland. The Mt Roskill section of the Ring Route is a $186m motorway extension, 4 km long and provides for 4 traffic lanes, a dedicated bus shoulder lane in each direction, a cycleway and a future rail line. The route includes 5 road bridges, 2 pedestrian bridges and several large anchored retaining walls up to 10m in height. The road bridges employ teeroff girders and DHC beams for the superstructure. The substructures comprise reinforced concrete piers and foundations. The pedestrian bridges are up to 170m long and comprise cable stayed main spans, precast concrete beams and columns, and reinforced concrete piled foundations. The longest bridge is the Hayr Road Motorway Underpass at 158m long. It has been constructed without expansion joints. Deletion of the expansion joints was considered beneficial as they typically require frequent inspections and ongoing maintenance. The two cable stayed footbridges provide for pedestrian and cycle traffic. The cable stayed system was selected primarily for its minimal structural depth but also to create a landmark structure on the new motorway.


  • English

Media Info

  • Pagination: 15p
  • Monograph Title: Innovation in engineered wood product bridge components

Subject/Index Terms

Filing Info

  • Accession Number: 01384467
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ATRI
  • Created Date: Aug 22 2012 4:35PM