Bridge Management: Four

Abstract

A great deal of attention has been centred in recent years on the assessment of the load carrying capacity of existing bridges. In contrast, the traffic loadings which bridges are required to carry are often notional and, consequently, in less heavily trafficked regions, they can be excessively conservative. BA79/98, on the management of sub-standard structures, recommends detailed load modelling for the accurate determination of the level of reliability of existing structures. Such modelling requires knowledge of advanced statistical concepts and thus is not practical for a majority of engineers. This paper describes the development of a simple statistical approach to determine the critical loadings to which a structure will be subjected without the requirement for complex statistical analysis. The background to the development of the simple statistical approach for the assessment of single lane, bi-directional highway bridges is presented. The simple approach is validated by comparison with a more complex statistical approach. Finally, the robustness of the approach is demonstrated for a number of different sites with different traffic flow characteristics. For the covering abstract see ITRD E106406.