How Do Australian Timber Bridges Stack Up? A comparative study with International Timber Bridge developments

Abstract

In 2006 the NSW Government announced a Timber Bridge Partnership program to upgrade timber bridges on regional roads. However, limited guidance was available to identify the most cost effective method of upgrading and at the time the most common construction methods available, involved concrete and steel. Hence, despite some timber bridges been replaced by new structures involving timber beams, many engineers and asset managers chose not to use timber. Two reasons for disregarding timber are the lack of adequate data about bridge reliability and lifetime cost. Other reasons relate to lack of knowledge, understanding, skill and confidence in working with timber. Examples are provided, firstly of some NSW bridges that have been part of the NSW Timber Bridge Partnership program and secondly of some overseas structures that have been cited in papers at recent international conferences. The outcomes address some of the research required to improve understanding of how to best upgrade the Australian bridge infrastructure. This paper provides an update and comparison of the state of the art timber bridge design and construction. Novel timber bridges have been recently constructed overseas, but many Australian designs are over 100 years old.