28 February 2016

Technical Talk – Wire Rope Safety Barrier post footings

New Zealand Transport Agency has just released a Technical Advice Notice ‘Wire Rope Safety Barrier Systems – post footing issues’. Click here to view.

This Technical Advice Notice discusses the issues arising with Wire Rope Safety Barrier (WRSB) post footings not being suitable size for the site’s soil conditions. If the footings are not fit for purpose they can result in poor system performance, increasing the risk of serious injury to vehicle occupants and result in increased maintenance costs due to foundation repairs.

For a WRSB to perform as designed and tested there needs to be adequate foundation support. All systems accepted by New Zealand Transport Agency including Armorwire and Brifen, have been tested in standardised soil (AASHTO M147 Grading A or B). Soil conditions outside this specification may result in the WRSB not performing as expected.

To comply with this Technical Advice Notice CSP has amended both the Armorwire and Brifen Installation and Product Manuals. These changes include:

  • Foundation shown for use in standardised soil conditions only, all other options have been removed.
  • Addition of horizontal force at a nominated height so the installation designer can design a site specific foundation when soils vary from standard.
  • Static pull test procedure included in both manuals to test that the foundation installed is fit for purpose.

The updated manuals are available to be downloaded from our website.