Seminar - Niphan Yaiaroon - The Reliability-Based Assessment of Existing Bridge Structures: Live Load-Effects Given by Various Australian Design Trucks

Wednesday 21 March 2007, 1.10 - 1.50 pm
Civil Engineering Lecture Theatre 3

Abstract
Bridges are considered as an essential part of the transportation network. There are the demands for new bridges and at the same time there are the needs to operate old bridges. In Australia, more than 50% of bridges are over 50 years old. The legal load limits have been continuously pushed to increase from industrial sections by operating longer and heavier vehicles on highways. Most existing bridges, designed according to the design codes at that time, are determined as unsatisfactory bridges because of the failure to satisfy structural requirements based on the current design standards. These may result in the replacement of bridges that are actually performing sufficiently in real locations. These emphasise the need for a better more realistic approach in evaluating the safety of existing bridges.

This presentation will briefly introduce the basic concepts of the main objectives in this research. The improvement of live load models, dynamic load allowance (DLA) and the procedures to achieve better realistic models will be discussed. Finally, the results of load-effects given by various Australian design trucks, analysed by load stepping method, will be compared and presented. The results will be used to determine the effectiveness of Influence Line method in determining peak load-effects for single-span simply-supported bridges and typical 3-span continuous bridges.