The performance of modular block walls reinforced with geogrid subject strong ground motions during the 2016 Kaikoura earthquake

The existing Dashwood Bridge on State Highway 1 over the railway line was a pinch point and quite dangerous with the high number of trucks using it. The bridge was built in 1932 in a continuous 4 span concrete beam, and no longer met the NZTA seismic standards. It was decided, due to the strategic route strategy risk, that a new structure was required with improved alignment across the railway. One of the main design considerations was the seismic load case (acceleration specified was 0.6g), because the structure is located only 12km from a large earthquake of Mw = 6.5 which occurred on 21st August 2013 (17km depth, and 20km east of Seddon). The 70-week project was started in January 2014 and the Keystone TW3 walls were started at the end of June 2014 taking approximately 1 month to complete the two walls, one at each end of the culvert. The 2016 Kaikoura earthquake occurred at two minutes after midnight on 14th November 2016 in the north eastern part of the South Island of New Zealand, with magnitude Mw = 7.8. This resulted in the Keystone TW3 reinforced soil retaining walls at Dashwood being subjected to an equivalent of the design ULS seismic event, with no signs of any distress.


  • English

Media Info

  • Pagination: 1136-40
  • Monograph Title: Proceedings of the 13th Australia New Zealand Conference on Geomechanics Perth, Western Australia, 1-3 April, 2019

Subject/Index Terms

Filing Info

  • Accession Number: 01714817
  • Record Type: Publication
  • Source Agency: ARRB Group Limited
  • ISBN: 9780994626103
  • Files: ITRD, ATRI
  • Created Date: Aug 26 2019 11:51AM