Parameter Study and Optimization of Slab Frame Bridges - Optimized Design Considering Environmental, Economical and Constructability Impact in a Preliminary Stage

Abstract

Abstract Slab frame bridges are one of the most common bridge types in Sweden with a potential in optimizing the design on the emissions from carbon dioxide and the costs. Older graphs with recommendations for dimensions of cross-sections published by the Swedish Road Administration, Vägverket (1996), are considered as conservative and outdated. This thesis presents updated dimensions that fulfils codes and standards that are used today. The optimization parameters have been identified through theory of slab frame bridges and a parameter study where different cross-sections have been analysed with respect to environmental, economical and constructability impact. The parameters have thereafter been optimized in a two-dimensional analytical study by implementing the moment distribution method and in a three-dimensional numerical study. Differences in the results between the different studies are discussed as well as the differences to the Swedish Road Administration’s graphs over preliminary dimensions. The theory of slab frame bridges and the parameter study show a correlation between the environmental and economical impacts where slender, heavy reinforced, cross-sections are to prefer when optimizing. Results from the preliminary design study shows a noticeable difference against the ones given by the Swedish Road Administration. Today’s standards and optimization techniques enables an optimized design of slab frame bridges, where a slender cross-section decreases the environmental impact to a lower investment cost.