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Vulnerability assessment of masonry historical monuments relies on the accurate assessment of their real structural and foundation conditions, which is always a very difficult and challenging task to determine. Ambient noise measurements are among the non-destructive field techniques, which can provide useful information regarding the structural integrity, the dynamic response characteristics of the structure and the dynamic properties of the foundation soil. The performance-based design approach developed in the research project PERPETUATE for the vulnerability assessment of monuments uses all this information in a cost efficient way. Moreover, validation of the whole methodology has been made on several monuments in the Medieval City of Rhodes. To illustrate the use of ambient noise measurements in the frame of PERPETUATE methodology, we performed a number of ambient vibrations measurements on three selected monuments in the Medieval City of Rhodes (Greece) and the surrounding soil. The aim was to identify the dynamic characteristics of the selected structures and the dynamic properties of foundation-soil where these structures are founded. The Frequency Domain Decomposition technique is adopted for ambient modal identification using ARTeMIS software and the continuous wavelet transformation for calculating the wavelet energy to compare it with the pathology pattern of a typical masonry wall. The dynamic properties of the foundation soil, in terms of shear-wave velocity, were also explored using the Spatial Autocorrelation Coefficient method. The goal of the ambient noise measurement performed herein is to better simulate the complex masonry structures in view of estimating their vulnerability using the PERPETUATE methodology and support rehabilitation decisions. The improvement of the initial numerical model using the results of the ambient vibrations measurements illustrates the usefulness of the approach and provides some helpful practical guidelines. [ABSTRACT FROM AUTHOR]

The assessment of historical elements at risk from earthquake loading presents a number of differences from the seismic evaluation of modern structures, for design or retrofitting purposes, which is covered by existing building codes, and for the development of fragility curves, procedures for which have been extensively developed in the past decade. This article briefly discusses: the hazard framework for historical assets, including a consideration of the appropriate return period to be used for such elements at risk; the intensity measures that could be used to describe earthquake shaking for the analysis of historical assets; and available approaches for their assessment. We then discuss various unique aspects of historical assets that mean the characterisation of earthquake loading must be different from that for modern structures. For example, historical buildings are often composed of heterogeneous materials (e.g., old masonry) and they are sometimes located where strong local site effects occur due to: steep topography (e.g., hilltops), basin effects or foundations built on the remains of previous structures. Standard seismic hazard assessment undertaken for modern structures and the majority of sites is generally not appropriate. Within the PERPETUATE project performance-based assessments, using nonlinear static and dynamic analyses for the evaluation of structural response of historical assets, were undertaken. The steps outlined in this article are important for input to these assessments. [ABSTRACT FROM AUTHOR]