Back calculation and model calibration for earthquake damaged bridges - a general procedure and its application to a highway viaduct

Seismic back calculation in structural engineering consists in the interpretation and reproduction of observed earthquake-induced damage patterns of structures. This article provides an overview of the methods used to this end in bridge engineering and presents a procedure for the back calculation. The methodological aspects, regarding investigations and modelling steps, are presented by a set of flowcharts. The procedure is applied on an existing Italian viaduct damaged during the L’Aquila 2009 earthquake. The damage state observed has been reproduced by an acceptable degree of precision indicating that the method can be a suitable tool for engineers facing this kind of problems.