Bridges

Each year, the Queensland Department of Transport and Main Roads (TMR) receives thousands of requests to allow innovative vehicles, cranes and heavy load platforms to access Queensland’s road and bridge network. The need to respond to these requests promptly, without compromising the safety of the network, has driven the development of a methodology for the rapid structural assessment of bridges. Three Assessment Ratios have been developed to facilitate these rapid structural assessments of bridges. TMR and the consulting industry have determined these Assessment Ratios for the bridges on the major state-controlled freight routes for a range of vehicle types and travel restrictions such as drive-line and travel speed.This paper describes the development and application of the Assessment Ratios that facilitate both the efficient processing of applications to access the state's bridges and the risk management of the network. The paper also highlights some of the observations drawn from the network-level analysis, including the observation that the reserves in strength to support modern multi-combination vehicles did not change significantly during the 50 years leading up to the introduction of the SM1600 loading in 2004.