Bridges

The recently completed Matahorua Gorge Bridge was constructed as part of a 3.1km realignment of State Highway 2 in Hawkes Bay, to remove a tight & steep section of highway. The project for the New Zealand Transport Agency (NZTA) was a design-build contract with main contractor Downer Ltd. The bridges were a design-build sub-contract to Concrete Structures Ltd with designers Holmes Consulting Group and McManus Geotech Ltd. The Matahorua Gorge Bridge crosses over a 70 m deep gorge; and is a three span continuous steel composite superstructure of 42.5 m, 52 m, 42.5 m spans and 137m overall length, supported on inclined steel braced piers, eliminating the need for tall vertical piers. The foundations for these inclined piers were excavated by hand some 20 m down the side of the gorge face. Both the constraints of the site and the location within a seismically active area influenced the design, and this paper explores the design and construction challenges and the chosen solutions for this bridge.