Probabilistic analysis of settlement-induced damage to bridges in the city of Amsterdam (The Netherlands)

The presence of highly compressible soft soil layers can expose infrastructure networks (roads, bridges, pipelines, etc.) to settlements that can compromise their serviceability or even their stability. The analysis/forecast of the induced effects can follow empirical, analytical, numerical approaches at different levels of analysis referring to samples of exposed elements whose number decreases as the level of required details increases. The present work proposes an original procedure for investigating bridge settlement-induced damage via the generation of empirical fragility curves based on the integration of visible damage surveys on statically indeterminate bridges (both masonry and concrete) with widespread remote sensing-derived settlement measurements. The procedure is tested in Amsterdam city (The Netherlands) worldwide famous for its dense network of bridges resting with their foundations on a subsoil of thick layers of organic clay and peat alternating with sands. These bridges currently suffer from settlement-induced damages of different severity that yearly require expensive maintenance and repair works. The obtained results seem promising under the perspective of prioritizing interventions on those bridges for which detailed and demanding coupled/uncoupled geotechnical-structural models need to be set up.