PSI - Issue 64

Christoph Brenner et al. / Procedia Structural Integrity 64 (2024) 1240–1247 Christoph Brenner et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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2. Materials and Methods 2.1. Description of the steel arch bridge as a case study

The development of the model database and the model selector is examined on a large-scale tied arch bridge with an orthotropic steel deck built in 1981, as depicted in Fig. 1. Spanning 91.0 meters, it accommodates two vehicle lanes and a footpath within a total width of 11.4 meters. After four decades of service, the bridge exhibits various damages, particularly at the welds connecting the hangers to the stiffening girders. In 2021, a loading test using a weighted truck was conducted to evaluate the bridge’s structural integrity, focusing on five load positions per lane. A single, central load position of the truck is selected for the further investigations in this paper.

Fig. 1. Sideview of the investigated steel arch bridge.

For the case study, a virtual damage state is assessed which involves cracks at a hanger connection in the middle of the bridge measuring 40 millimeters on both sides, reminiscent of existing damages at the welds. The damage is included in the simulation model by separating the top flange of the stiffening girder and the web of the hanger over the distance of the cracks. As there is no extensive SHM system on the bridge, only synthetic measurement data from a virtual SHM system is used in the following. Therefore, a systematic approach was implemented, with sensors placed regularly on both upper and lower flanges of the stiffening girders, along with placements on the lower flange of the cross girders, totaling 151 sensors. These sensors measure strains longitudinally on the stiffening girders and transversely on the cross girders. The sensor positions are shown in the geometric model in Fig. 2.

Fig. 2. Geometric model with highlighted sensor positions.