Visualisation, modelling and parametric analysis of an elevated guideway structure for condition assessment

Abstract

Several studies on analytical and experimental evaluation of various types of highway bridges are available in the literature. However, there are very few studies on the modelling and analysis of transit guideways, which are unique structures in terms of their geometric and structural details. This study explores the condition of an existing transit guideway system that has been in service for 35 years. The structural system is composed of six-span continuous prestressed concrete bridge segments. The overall guideway system incorporates a number of continuous bridges that share common design details, geometries and loading conditions. The original design analysis of the structure was based on certain simplifying assumptions of complicated mechanisms such as rigid behaviour over supports and simplified tendon–concrete–steel plate interactions. The current objective is to conduct a representative study for a more accurate understanding of the structural system and its behaviour for decision making. Due to the unique and complex structural details, it is shown that visualisation is the first step for conceptualising the system behaviour. Then, the structural behaviour is described using finite element models, and static and dynamic parameter sensitivity studies are conducted for characterising the performance under service loads. Parameter sensitivity studies consider the effect of changing critical parameters, including material properties, prestress loss, and boundary and continuity conditions, on the static and dynamic structural response. This study provides information about critical components of the guideway. It serves as a benchmark, presenting a procedure and methodology for modelling a guideway structure for future evaluations, to help make better decisions for operations, maintenance and safety requirements.

Keywords:

• guideway
• FEM
• post-tension
• prestressed
• maintenance
• monorail

Acknowledgements

This study is based on the MSc thesis of the first author. The second author served as the advisor for this study. Several colleagues, associates and fellow graduate students provided feedback and resources during the development of this study. The authors would like to acknowledge all those who gave their time and support by reviewing the thesis, providing data and offering feedback.

 The second author would also like to thank Professor Hitoshi Furuta from Kansai University, who shared his insight about monorail guideways during the second author's visit to Japan in 2007. Engineers and administrators from Osaka Monorail Company are also appreciated for exchanging their ideas and experiences about monorail guideways. Finally, Ms Naeko Takahashi, graduate student at the University of Central Florida, is greatly appreciated for her diligent translations from Japanese to English.