Evaluation of the Performance of Unreinforced Stone Masonry Greek “Basilica” Churches When Subjected to Seismic Forces and Foundation Settlement

Abstract

Unreinforced stone masonry made of low strength mortar has been used for centuries in forming old type stone masonry churches of the “Basilica” typology. The seismic performance of such stone masonry structures damaged during recent strong seismic activity in Greece, combined with long term effects from foundation settlement, is presented and discussed. A simplified numerical process is presented for evaluating the performance of such damaged stone masonry structures, making use of linear and non-linear numerical tools and assumed limit-state failure criteria. In order to obtain a quantification of the in-plane sliding shear failure criterion, a number of stone masonry wallets were built with weak mortar and were tested in the laboratory. Through the comparison of the obtained numerical predictions with the observed structural behaviour for selected cases of stone masonry “Basilica” churches, the validity of the applied simplified numerical process is demonstrated. It is shown that reasonable approximation of the observed performance of such structures can be obtained when the assumed failure criteria are realistic.

The 30th of October Samos-Greece Earthquake. Issues Relevant to the Protection From Structural Damage Caused by Strong Earthquake Ground Motions

“…This is covered in many past publications. One category of structures with a heavy toll is old Christian Orthodox churches (Manos and Kozikopoulos, 2015;Manos, Soulis, Karamitsios, 2012;Manos and Karamitsios, 2013;Manos, 2016;Manos, Kotoulas and Kozikopoulos, 2019;. Another type of vulnerable buildings are those with particular architectural features which were declared to be under conservation; this means that the owners should abide with a particular legislative framework dictating the rules of any works to be done in such a structure (Manos and Papanaoum, 2009).…”

Unreinforced Stone Masonry Churces in Greece Under Gravitational and Earthquake Actions

“…In this way, the validity the relevant dynamic system, formed in this way, can be checked and properly adjusted. d) Critical structural elements with stress concentration regions can be identified ( [20], [23]). e) Using parametric studies the influence of various parameters, either regarding the actions or the structural formation (e.g.…”

“…The simplified process described in section 2 is utilized. The flexibility of the soilfoundation interface was approximated by utilizing equivalent linear link elements which were assigned axial low axial stiffness value to approximate in this way the potential for soil settlement in the vertical direction ( [19], [20]). Two distinct cases of soil-foundation flexibility are considered.…”

Study of the Influence of Underlying Soft-Soil Layers on the Dynamic and Earthquake Response of Bell Towers

“…This resulted to significant international research effort that includes in-situ monitoring of the response of bell towers on a temporary basis, like the one attempted here, or more sophisticated and on a permanent basis Foundation problems for bell towers are evident in many case the most celebrated being Pisa's grand bell tower in Italy, that is quoted as a major medieval engineering error. Therefore, the soil flexibility is also an area of research interest for these structures especially when their dynamic and earthquake response is under investigation ( [19] to [28].…”