Fragility analysis of heritage masonry buildings accounting for ageing effects

A methodology is presented for assessing the time (age) dependent seismic fragility of heritage buildings, an issue that has hardly been addressed so far. Age effects are explicitly considered for the parameters (compression strength and shear strength of masonry) for which the available data permits the development of time-dependent models, while effects on stiffness and deformation parameters are accounted for in an indirect way. The methodology entails response history analysis of three-dimensional models of the masonry building and assignment to a damage state by appropriately interpreting the deformations of critical zones calculated from the analysis. The methodology is applied to an actual heritage building located in a high seismicity area (Greece). Sets of fragility curves are derived using alternative assumptions for key parameters related to the definition of global damage state for the building, and recommendations are made for future research needed on this topic that is particularly important for the preservation of cultural heritage in an era wherein environmental conditions become more challenging.