This paper investigates the influence of the scour on the modal properties of a multi-span masonry arch bridge located in Central Italy, which suffered the collapse of two spans after a very severe flood in 2013 and the collapse of two more spans during another major flood event in 2016. An experimental campaign was carried out to characterize the dynamic properties of the remaining spans in terms of vibration frequencies and modal shapes. For this purpose, ambient vibration tests were performed, complementing the information already available from material characterization tests. In the first part of the paper, a finite element model of the remaining bridge portion is developed and calibrated using measured dynamic test data. Subsequently, an advanced nonlinear model of the full bridge is built to simulate the scour progression and assess the modal response variation for different levels of scour. Results show a non-negligible variability of the transverse modal shape even at the early stages of the scour phenomenon, therefore calling for a deeper investigation in order to evaluate the suitability of the OMA (Operational Modal Analysis) based identification technique for scour monitoring purposes.
Dynamic properties of a masonry arch bridge subjected to local scour up to failure
F. Scozzese;
2019-01-01
Abstract
This paper investigates the influence of the scour on the modal properties of a multi-span masonry arch bridge located in Central Italy, which suffered the collapse of two spans after a very severe flood in 2013 and the collapse of two more spans during another major flood event in 2016. An experimental campaign was carried out to characterize the dynamic properties of the remaining spans in terms of vibration frequencies and modal shapes. For this purpose, ambient vibration tests were performed, complementing the information already available from material characterization tests. In the first part of the paper, a finite element model of the remaining bridge portion is developed and calibrated using measured dynamic test data. Subsequently, an advanced nonlinear model of the full bridge is built to simulate the scour progression and assess the modal response variation for different levels of scour. Results show a non-negligible variability of the transverse modal shape even at the early stages of the scour phenomenon, therefore calling for a deeper investigation in order to evaluate the suitability of the OMA (Operational Modal Analysis) based identification technique for scour monitoring purposes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
