Christchurch ground improvement trials

About this document

  • Published on 23 March 2012
  • Of interest to Geotechnical engineers
  • 1st edition


If you are a geotechnical engineer you may be interested in the results of ground improvement trials in Canterbury. These were to find ways to strengthen land prone to liquefaction.

Repairing and rebuilding houses affected by the Canterbury earthquakes supplementary guidance.

MBIE will use the trial results to develop technical guidance to repair and reconstruct foundations in Canterbury’s TC3 areas.

The 4 options trialled were:

  1. cement-stabilised two-metre-thick raft over the building platform – formed by excavation, mixing and recompaction or in-place mixing
  2. deep soil mixing columns – constructed in a grid pattern to provide 15-20 per cent ground coverage beneath the building
  3. perimeter curtain wall – to form a protected cell around the building
  4. densification by excavation and recompaction or by dynamic compaction – dropping weights repeatedly in order to make the ground beneath the building denser.



This information is published by the Ministry of Business, Innovation and Employment’s Chief Executive. It is a general guide only and, if used, does not relieve any person of the obligation to consider any matter to which the information relates according to the circumstances of the particular case. Expert advice may be required in specific circumstances. Where this information relates to assisting people: