Interdisciplinary study of dynamic behavior and earthquake response of Hagia Sophia

Abstract

Structural analyses of the Hagia Sophia, a sixth century masonry edifice, in Istanbul, Turkey, are coordinated with geotechnical and material investigations to provide insight into the structure's response to dynamic loads. The church contains four great brick arches springing from stone piers that offer primary support for a 31-meter diameter central dome and two semidomes. Stone and brick masonry material properties for the numerical model are adjusted to match system mode shapes and frequencies identified from measured response to a recent low-intensity earthquake. The calibrated model is used to predict the measured responses, and improvements achieved by incorporating soil-structure interaction are demonstrated. Stresses under simulated severe earthquake loading are estimated at the critical locations in the arches. The materials of the mortar are studied in detail using a number of preliminary microstructural, mineralogical, and chemical tests to support the choice of effective mechanical properties. The foundations of the main piers and soil surrounding them are studied through preliminary tomography experiments to support the modeling of soil-structure interaction.