Northport Dry Dock and Western Reclamation

Marsden Point, Whangarei

Project Detail

This project involves Reclamation for a new Dry Dock Facility at Marsden Point. The project includes:

  • Construction of a dry dock facility
  •  Dredging for a deep turning basin
  • Reclamation using dredged material.
  • Extensive geotechnical laboratory testing of dredging materials to assess suitability as fill

Estimated Project Value: $50-70M

Initia's involvement

Our involvement in this project has comprised the following:

  • Extensive desk study of all the historical ground data for Northport
  • Geotechnical investigations comprising overwater barge drilling with boreholes and CPTs
  • Development of detailed ground models

Estimated Project Value: $240M

  • Liquefaction assessment of material types
  • Settlement assessment due to reclamation fill
  • Earthworks assessment of the reclamation materials
Geotechnical risks and mitigation

RISKS

MITIGATION
Liquefaction susceptibility of the reclamation material. The site is underlain by interbedded marine and alluvial deposits with the potential to liquefy. With targeted geotechnical testing and liquefaction analyses we were able to demonstrate that liquefaction related effects could be largely controlled or mitigated. There are discrete areas of liquefiable sands in the upper material but testing indicated that the clayey sands would not liquefy.
Consolidation settlement of proposed reclamation fill. The ground beneath the proposed reclamation area is typically granular in nature.
 Given the thickness of the proposed fill, the underlying natural ground will consolidate and recommendations were made to give certainty around timeframes.

Client Referee
Grey Blomfield, Northport Ltd

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