Structural Categorization and Capacity Comparison of Standard-Classified Bridges A support for bridge management assessment

Abstract

This master’s thesis was carried out in collaboration with the Transport Administra tion and examines bridges with standard classification. The aim is to support future prioritization and analysis of around 3000 such bridges. This was done by studying the relationship between calculated load-bearing capacity and previous classifications, and by identifying patterns related to bridge structure, construction year, and regulation framework. The main focus of the study is beam bridges, beam frame bridges, slab frame bridges, and slab bridges. Arch bridges and culvert bridges were also considered on a gen eral level. The results are based on comparisons between previous standard values and newly calculated A- and B-values. The analysis was carried out using bridge data ob tained from BATMAN. The results show that the standard classification is generally representative, but there are significant variations between individual bridges, meaning the standard values do not always reflect the actual load-bearing capacity. Most bridges showed higher calculated capacities than their previous values, while some were lower. However, none were downgraded to a lower load-bearing class. Since the results are based on a limited number of bridges, it is difficult to establish clear general trends. Nevertheless, certain patterns were identified for different bridge structures, which may be relevant for further evaluation. Slab frame bridges show the greatest variation in calculated values and also constitute to the largest group of bridges that still remain under standard classification, making them particularly interesting for further investigation. The conclusion of the study is that the process of comparing standard values with cal culated load-bearing capacities is complex, as several factors influence the final assess ment. The work demonstrates that certain bridge groups may be of particular interest for further investigation and that the results can support future prioritization and man agement of standard-classified bridges. Key words: Load-bearing capacity, standard classification, load-bearing assessment, A-value, B-value, Swedish Transport Administration, bridge structures, load-bearing class, BATMAN, regulations