Numerical simulation of the dynamic and earthquake behavior of Greek post-Byzantine churches with and without base isolation

Abstract

dynamic and earthquake response of Post-Byzantine stone masonry churches, which were subjected to a damaging earthquake sequence in the region of Western Macedo- nia in Greece, is studied. Two structural systems of the basilica form are first examined. Apart from these two basilica churches, the behavior of another much older church, which represents a much simpler orthogonal structural formation, is also examined. This is a two- story church with a simple orthogonal vault and a wooden roof that belongs to an 11th centu- ry monastic-complex. Two of these churches are also studied together with the introduction of a base isolation system. performance of each of these three distinct structures is studied under the combination of the gravitational and seismic forces. 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. seismic damage, due to a relatively recent strong earth- quake sequence, is utilized to validate the realism of the numerical predictions. 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 (Ca- pacity/Demand > 1), which is assumed to indicate acceptable structural performance. How- ever, the introduction of base isolation under an existing old stone-masonry structure is also faced with considerable difficulties, despite the advantages that are shown by the results of numerical investigation. In the particular case of The Church of Virgin Mary of Tour- niki these difficulties must be faced because this old church has to be moved in a different location due to flooding. Thus, the placement of a base isolation scheme under this structure in its new location is a feasible solution for this particular case with no significant extra cost. Obviously, thus base isolation scheme should be considered in addition to all other tradition- al repair and strengthening measures for this church.