new zealand: special issue introduction

The Otira Viaduct is a 445m long prestressed concrete box girder bridge recently constructed in the Southern Alps of New Zealand. The site is set in majestic mountains high in the Arthur’s Pass National Park. The area’s geological, geotechnical and environmental conditions, together with the terrain and active river conditions, made this an unusually challenging and demanding project. This paper describes the design and construction of the balanced cantilever bridge, which has spans up to 134m and piers constructed deep into avalanche material with rock compressive strengths of up to 250MPa. Ian J. Billings, BE (Hons) FIPENZ Beca Carter Hollings & Ferner Ltd, Auckland, New Zealand Richard J. Holyoake, BE (Hons) MIPENZ Beca Carter Hollings & Ferner Ltd, Christchurch, New Zealand

Innovations in the design of structures to resist earthquakes in New Zealand over recent years are discussed. These include the ductile design approach incorporating capacity design, and the detailing of reinforcement to ensure ductile behaviour, design using seismic isolation and mechanical energy dissipating devices, the use of precast concrete in buildings, and the assessment and upgrading of the earthquake resistance of existing older structures. R. Park, OBE, ME, PhD, Hon DEng, FREng, FIStructE, FICE, FRSNZ, FIPENZ Emeritus Professor of Civil Engineering University of Canterbury, New Zealand