Road widening in a New Zealand alpine pass

摘要

The Candy's Bend to Starvation Point project is an 850m length of state highway in the Southern Alps of New Zealand between Canterbury and the West Coast on the South Island (see Figures 1 and 2). It is approximately 62 miles from Greymouth and 93 miles from Christchurch. This construction follows the replacement of a particularly hazardous section of the highway with the Otira Viaduct in 1999. The site has long been prone to rockfall and the existing road was single-lane for much of its length. The objective was to construct a cost-effective two-lane road on an extremely complex site and over extremely challenging terrain on behalf of the client, Transit New Zealand. The solution incorporates a number of unusual concrete structures. These include two overhead rockfall protection structures, a propped 'half bridge', and a cantilevered 'half bridge'. The construction cost was approximately NZ$10.5m.