P 978 – Holistic Assessment of Steel and Composite Railway Bridges according to Criteria of Sustainability
For our infrastructure railway bridges have a significant importance. They are designed for a scheduled life time of 100 years. Nowadays, aspects helping to implement planning and management procedures supporting the goal of a sustainable development become more and more important. Although bridges are characterized by an extremely long lifetime, actual assessment approaches and selection criteria of railway bridges are mostly based on the erection costs. Within this re-search project lifetime related advantages and durability aspects of steel and composite railway bridges are to be determined by conducting life-cycle analyses of different bridge types integrating aspects helping to create sustainable structures. The analyses is carried out by applying the three model based methods life-cycle costing, life-cycle assessment and the calculation of operation encumbrance costs for bridges. Especially for railway bridges, which are stressed with high and cyclic loads the durability of single construction details plays a decisive role. If the durability cannot be guaranteed for a life-time of 100 years complex rehabilitation measures have to be applied. This results in increased maintenance work and associated higher costs. Additionally, the regular train operation is interfered and obstructions result, which finally turn into an economical damage.
Therefore, for the three defined reference bridges especially fatigue relevant details are investigated. As an example, for specimens representative for thick plates of trough bridges the multiaxial fatigue behaviour was experimentally examined. The findings of the detail analyses result in an improved safety level or lead to a prolongation of the life span. The life span is a basis for the life-cycle analyses of bridges that are performed by addressing the three dimensions of sustain-ability. Interalia, the methodological findings of the previous FOSTA project P 843 “Holistic assessment of steel and composite bridges according to sustainability criteria” are used for the holistic assessment. This project focusses on sustainability assessment of highway bridges. The methods can partly be adapted to the requirements of railway bridges. To some extend the development of new calculation methods meeting the specific demands of railway bridges must be performed.
Another aim of this research project is the calculation and assessment of steel and composite railway bridges mainly using model-based calculation approaches.
By conducting analyses of different types of reference bridges with different span widths the most important and relevant parameters affecting the results depending on the location specific boundary conditions are identified. Furthermore, for all types of bridges the impacts resulting from the erection stage are crucial for the overall results. This is valid for the life-cycle costs and for the results of the environmental analyses as well. If an optimization of the construction processes is performed it can result in increased erection costs. At the same time a significant reduction of the operation encumbrance costs is possible. Only by performing holistic and quantitative analyses all influences on the results can be integrated into a decision-making process.
The research project (IGF-Nr. 458 ZN) was carried out at Institut für Konstruktion und Entwurf, Universität Stuttgart, an der Versuchsanstalt für Stahl, Holz und Steine, KIT, am Lehrstuhl für Metallbau, TU München und am Lehrstuhl für Bauphysik, Universität Stuttgart. FOSTA has accompanied the research project work and has organized the project funding from the Federal Ministry of Economics and Technology through the AiF as part of the programme for promoting industrial cooperation research (IGF) in accordance with a resolution of the German parliament.
Only available in german language.