ABSTRACT
In order to establish a sustainable bridge assessment within a practical planning routine, it is necessary to reduce the calculation effort by applying automated algorithms. Information generated by the application of Building Information Modeling (BIM) can be used as project-specific input data for this purpose. For the method of life cycle assessment (LCA), the approach of linking the materials of the BIM-model with environmental data sets to calculate the ecological impacts has become widely established. This material-based approach provides sufficiently accurate results for an ecologic assessment in late planning phases. For early planning phases it is not directly applicable and the approach is not transferable to the application of the calculation methods life cycle costing and macroeconomic cost calculation.
The approach presented in this paper introduces a framework that can be used to calculate the life cycle impacts of a bridge by linking the objects of a BIM-model with the content of a hierarchically structured catalogue of elements. To establish this catalogue, individual items are pre-balanced and combined to generate base elements. To represent the entire life cycle of a bridge, follow-up elements, which occur after a specific time interval within the use and dismantling phase, are additionally defined. The individual base elements are combined into generalized major and macro elements into which the individual base elements are included with statistical shares. By applying the different element types, it is possible to use BIM-bridge models with different levels of detail for a holistic assessment and to include all impacts that occur during the complete life cycle.
