ABSTRACT
Many bridges in the Netherlands were built during the 70’s and as such were not designed for today’s traffic. As a consequence the Dutch Ministry of Infrastructure and the En-vironment initiated a program in which existing bridges are inspected and in selected cases the load-capacity is assessed by numerical analysis. One such bridge, in the north of the Netherlands, is a 17-span double-box girder bridge with a length of 974 meters and width of 16.85 meters. During inspection, shear cracks were observed in the webs. This bridge has subsequently been analyzed using the newly developed “Stiffness Adaptation” (STiffness ADAPtation) method in the DIANA Finite Element program [de Boer 2010]. The method allows prediction of crack patterns, crack widths and onset of reinforcement yielding. A new and efficient modelling and analysis strategy has also been developed for the assessment. In this strategy a BIM compliant 3D solid model is generated, based on the CAD data for the bridge. Automatic mesh generating procedures are used such that all details can be realistically modelled in a reasonable time. This paper shows a new approach for both the design and assessment of structures using 3D finite element analysis. It can be seen from the results that this can be used for very detailed models while significantly reducing run times with improved confidence in the outcome.
