Although Module 4 was offline for a short time, it’s now back up on the website (in our library section) as well as being available via the MBIE Geotechnical Education webpage.
Please have a read and review, sending any feedback or Qs through to modulefeedback@nzgs.org.
Module 4 provides the principles for good foundation design which brings practice up-to-date and implements recommendations from the Royal Commission. We recommend that practitioners make themselves familiar with it and apply the guideline principles in their designs. Feedback during this public comment period will inform decisions about the future direction of B1/VM4 (verification method for foundation design). B1/VM4 hasn’t been updated for some time and it has quite limited application. It does not address liquefaction-prone sites or those with other stability issues. Some aspects of Module 4 may be perceived as being inconsistent with B1/VM4, particularly related to strength reduction factors. However, shallow footing design is mostly governed by settlement considerations in the serviceability case, so the change will be minimal in these cases. For deep foundations, Module 4 references AS2159: 2009 to provide a risk based approach to strength reduction factors.