Canterbury earthquakes and pavement resilience

Following a request from the Christchurch Infrastructure Rebuild Alliance, the authors led an investigation to assess the performance of various pavement structures used in Christchurch and surrounding districts. The objective was to identify the best performing/most resilient pavement structure designs to adopt for the rebuild of Canterbury roads affected by the recent earthquakes. The investigation included a comprehensive review of international literature, site inspections, laboratory testing, and canvassing maintenance contractors, Christchurch City Council, NZ Transport Agency and consultant engineers to ensure that the investigation included all relevant issues. Following comprehensive site inspections and detailed analysis of data and photographs, five main failure mechanisms caused by the seismic events were identified. The different mechanisms and recommended solutions are explained in the paper, and some key findings are: The most resilient pavements in seismic events, considering factors such as level of service after the event(s), survivability of the pavement and economics of repair, are thin-surfaced unbound granular and foamed bitumen stabilised pavements. The aggregate in unbound granular pavements could be contaminated with up to 30 per cent liquefaction material without adversely affecting its performance. A thicker, stiff structural asphalt and concrete pavement could, in theory, constrain the upward movement of liquefaction material, but no evidence was found to support this concept. Instead, liquefaction was often trapped under asphalt, and created bulges. The only feasible approach to repairing these bulges is to remove the asphalt and the underlying material, and replace with new construction. Liquefaction caused unreinforced concrete slabs to tilt and/or crack. Surfacing treatment should be as per normal using normal surfacing treatment selection criteria, but the rebuild designs need better adhesion of the surfacing to the pavement.

Language

  • English

Media Info

  • Pagination: 7p
  • Monograph Title: Public works: explore new territory: IPWEA International Public Works Conference, Darwin, NT, 11-15 August 2013

Subject/Index Terms

Filing Info

  • Accession Number: 01495611
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ITRD, ATRI
  • Created Date: Oct 17 2013 10:09AM