The dynamics of a parabolic arch is studied in its undamaged and damaged states. The damage consists of a notch that reduces the height of the cross section at a given abscissa. A damage identification technique, based on the minimization of an objective function measuring the differences between numerical and experimental variations of natural frequencies for undamaged and damaged states, is used. The uniqueness of the solution in different damage configurations is investigated using pseudo-experimental data and the reliability of the identification procedure is assessed. The identification procedure is then applied to an experimental case, where frequencies are obtained by impulsive tests on a prototype arch. The minimum number of experimental data needed to identify damage parameters is defined and the sensitivity of the identification algorithm to different possible choices of sets of data is analyzed.

Extensive measurements of the dynamic response of the Colosseum induced by road traffic were performed. The vibration level was evaluated in accordance with international standards to investigate the potential for structural damage. Using only the response, the natural frequencies and mode shapes of the monument were determined and compared with numerical ones, which were obtained by a finite element model. The mechanical properties of the model were updated in order to adapt the analytical response to the experimental one. Details of the test methods, measurements and analysis procedures and the major findings of the investigation are presented. Copyright © 2008 John Wiley & Sons, Ltd.