The seismic safety of two medieval masonry bell towers in Italy is investigated. At first, compressive tests, flat jacket tests and environmental vibration measurement are used for structural identification. In particular, a vibration-based procedure is used to investigate the dynamic features of monuments dealing with the uncertainties due to the mechanical characteristic of the material. The procedure is based on a typical finite element (FE) model updating technique using environmental vibration test results. The updated FE model of the towers is defined from a set of parameters minimizing an error criterion relative to modal properties. A satisfactory improvement on modal parameters which is in close agreement with the experimental results is found. The seismic assessment is carried out with nonlinear static analysis of the tower under multimodal distributions of lateral loads. Nonlinear analysis shows the potential collapse mechanisms and evidences the dangerous characteristics which may play a role in seismic vulnerability of the towers. A displacement-based version of the capacity spectrum method based on the inelastic demand spectra is finally used to evaluate the seismic performance of the towers at the different limit states.
Structural monitoring and seismic safety of two masonry bell towers
FERRAIOLI, Massimiliano;MANDARA, Alberto;
2010
Abstract
The seismic safety of two medieval masonry bell towers in Italy is investigated. At first, compressive tests, flat jacket tests and environmental vibration measurement are used for structural identification. In particular, a vibration-based procedure is used to investigate the dynamic features of monuments dealing with the uncertainties due to the mechanical characteristic of the material. The procedure is based on a typical finite element (FE) model updating technique using environmental vibration test results. The updated FE model of the towers is defined from a set of parameters minimizing an error criterion relative to modal properties. A satisfactory improvement on modal parameters which is in close agreement with the experimental results is found. The seismic assessment is carried out with nonlinear static analysis of the tower under multimodal distributions of lateral loads. Nonlinear analysis shows the potential collapse mechanisms and evidences the dangerous characteristics which may play a role in seismic vulnerability of the towers. A displacement-based version of the capacity spectrum method based on the inelastic demand spectra is finally used to evaluate the seismic performance of the towers at the different limit states.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
