An 11 kilometre stretch of Kawhia Road has presented geotechnical issues to Transit and their contractor Transfield Services. Over the five year period that Transfield Services has worked on the PSMC 001 contract for Transit there have been seven large failures and numerous small failures along this 11 kilometre stretch, usually triggered by rainfall. The chosen and most practical solution is to reduce the effect that rainfall has on the terrain surrounding the road by improving the road drainage system. Works included; water table improvements; kerb and channel installation; hydroseeding; and some culvert improvements. These types of solution reduce the risk to the road surface in the case of heavy rainfall. By working proactively on this section of road, the likelihood of slopes becoming saturated enough to fail catastrophically is markedly reduced with minimal cost to Transit. (a) For the covering entry of this conference, please see ITRD abstract no. E212706.
Abstract