SEISMIC STRENGTHENING AND REPAIR OF BYZANTINE CHURCHES

Abstract

Experimental and analytical investigations were performed to verify an original methodology that was developed for the repair and seismic strengthening of Byzantine churches. This work was part of the long-term research project entitled Study for Seismic Strengthening, Conservation and Restoration of Churches Dating from the Byzantine Period (9th-14th century) in the Republic of Macedonia. The project was realised jointly by the Institute of Earthquake Engineering and Engineering Seismology (IZIIS)—Skopje, the Republic Institute for Protection of Cultural Monuments (RZZSK)—Skopje, and the Getty Conservation Institute (GCI)—Los Angeles, California. A model of St. Nikita church was constructed to a scale of 1:2.75 and tested on a seismic shaking table simulating the existing and the strengthened state to investigate the linear behaviour, non-linear behaviour, and behaviour in the heavily damaged state (close to failure). To investigate the non-linear dynamic response of the structure, an original trilinear model of stiffness degradation and pinching of the hysteretic loop was developed on the basis of the experimental results obtained for the original and the strengthened model as well as from the results of the quasi-static testing of wall elements. This model allows successful modelling and description of the behaviour of the church structures in all phases of behaviour: elastic range, non-linear range (occurrence of cracks), sliding range, and the heavily damaged range that resulted in failure.