title: A Proposed Strategy for Upgrading Bridge Infrastructure Network : to meet the demandss of Australian transport industry
Creators: name: Muhunthan, Thanabalasingam (Bala)
Publisher: name: Griffith University
Year: 2008
Subjects: subject: Transport industry
subject: Bridges designed

description: Abstract : Bridges are important links in the road network. Over the years, bridges have been designed to various standards as they were built in different periods. The road infrastructure grew as the country developed and the population spread out. The technology also has significantly developed in structural assessment of bridges, resulting in better understanding of bridge structures and their behaviour. As funds availability is tightened, road authorities around the world are facing challenges related to the implementation of optimal bridge management programs based on lifecycle cost, remaining life and bridge capacity considerations. This has led to public expectation of wise spending of funds which wisdom requires proper prioritisation of bridge repair, rehabilitation, maintenance, and replacement projects. The bridges in the network are checked for capacity only when there is a proposal to introduce new operational vehicles or to increase existing legal load limits. This also happens when a single operator wants to introduce a truck with new axle configuration. A strategy is required to upgrade bridges on sub-networks in a proactive way in anticipation of new operational loads or legal limits being imposed. This PhD research project will investigate the different design standards that have been used to design bridges in Australia, and the different operational loads that are currently in use on Australian roads. The research will determine service levels that can be applied to sub-networks in terms of operational loads, and develop a methodology to identify bridges that require upgrading in a sub-network. The options for upgrading can be developed based on this methodology; the economic benefits can be measured in terms of the cost to upgrade a particular part of the overall network from one service level to another and the cost benefit from increased freight movement on the upgraded route. While estimating the cost of upgrading, various repair and strengthening methods will be considered with special emphasis on bridge capacity. Appropriate decision-making tools in route upgrading will be identified and their application demonstrated. These tools will assist the bridge planners and managers attached to road authorities to analyse their bridge network, identify sub-networks in terms of introducing appropriate service levels, and look into the logistics of manoeuvring different operational loads from one part of the state to another via identified routes The current network status assigned to roads is based solely on pavement management requirements. It is proposed that in this PhD research the network status will be extended to bridges as well to determine the required service level of the bridges in terms of bridge capacities required for operational loads. In summary, the primary objective of this research is to develop a strategy that will determine required service levels for routes based on service levels and the secondary objective is to develop methods, models and identify tools to assess the cost effectiveness of alternative bridge management solutions for individual bridges and networks. It is more economical to have sub-networks identified with a service level for use by certain operational load or loads. This will allow the road authorities to make maximum use of the capacities of the existing bridges in that sub-network rather than upgrading all the bridges in the whole network to accommodate the highest operational load or satisfy a new design standard.