Emergency Slip Repairs

Services: Ground Anchoring, Soil Nailing, Slope Protection

Main Contractor: Lindesay Construction

Engineer: Tonkin & Taylor

Grouting Services wins the SME awards for Category A (projects under $500,000) at the 2017 Hynds Construction Awards
Peter Ensor

A prime water front site in Auckland has a coastal perimeter that is formed by steep cliffs with mature Pohutukawa trees and other low vegetation growth. Significant periods of high rainfall resulted in a significant slip near the main dwelling.

During a site walkover it was also noticed that a crib wall which runs parallel to the beach, and, the access driveway to the dwelling was showing various signs of distress. The risks on the project were numerous and included the geographical location and relative isolation from the land, climatic conditions, variable ground and the environmental impact on the adjacent marine area. A significant amount of collaboration and co-ordination between all parties was required to mitigate the risks.

The only access to get plant and material to this ‘isolated’ section of beach in one of Auckland´s most exclusive suburbs was by barge. This required thorough planning and co-ordination around the tides. The work was predominantly carried out from the beach and this presented challenges for all parties in terms of plant and material security given the high tide came right in to the work face. The environmental controls were monitored throughout the day. Marine protection was maintained by a large floating boom and smaller environmental controls that were set up for specific tasks.

A team of experts was assembled and Grouting Services worked closely with the engineers, main contractor and other sub-contractors to develop a design that was buildable, cost-effective and efficient.

The emergency slip repairs and ground stabilisation works undertaken by Grouting Services included;

  • installation of temporary anchors to failed retaining wall to prevent timber poles rotating further
  • installation of permanent BluGeo GRP bar anchors at the top of the slip as part of a tied back piled retaining wall
  • installation of temporary soil nails and slope protection system comprising steel bar and Macmat-R to allow the construction of a new crib wall and sprayed concrete wall to proceed
  • installation of GRP anchors coupled with steel bearing beams to prevent collapse of the lower crib wall
  • permanent soil nailing and slope protection works to an adjoining slip on the property
Contact Us +64 9 837 2510