Earthquake numerical simulation of the dynamic and earthquake behaviour of Greek Post-Byzantine churches with and without base isolation

摘要

The dynamic and earthquake response of Post-Byzantine stone masonry churches, which were subjected to a damaging earthquake sequence in the region of Western Macedonia in Greece, is examined. One of these "Basilica" form churches is studied numerically; moreover, the study extends to the behavior of a two-story box-type church with a simple orthogonal vault and a wooden roof, which belongs to an 1 lth century monastic complex. These two structures are also studied together with the introduction of a base isolation system. The predicted performance of the various structural elements, located at the peripheral masonry walls, is then checked by applying an assumed Mohr-Coulomb failure envelope that is believed to represent the limit-state stone-masonry behavior. The numerical introduction of a base-isolation system was quite effective in lowering the demands and thus resulting for most structural elements in Capacity/Demand ratio values larger than one, which is assumed to indicate acceptable structural performance. However, the introduction of base isolation under an existing old stone-masonry structure is also faced with considerable difficulties, despite the favorable results of the numerical investigation. For "The Virgin Mary of Tourniki" these difficulties must be faced because this old church has to be moved to a different location due to flooding. Thus, introducing a base isolation scheme under this structure in its new location is a feasible solution for this particular case with no significant extra cost.