Global Seismic Strengthening Center (SGM)

An earthquake is a natural event marked by abrupt and violent shaking of the ground, which is frequently triggered by the movement of tectonic plates beneath the Earth’s surface. These motions occur along faults, which are breaks in the Earth’s crust where plates have moved past one another. The energy released during it travels as seismic waves, causing significant damage to buildings, infrastructure, and landscapes and potential loss of life. They can vary widely in magnitude and severity, with consequences ranging from barely discernible vibrations to catastrophic disasters that transform entire regions.

Analysing and strengthening historical structures are challenging task due to the geometrical complexity and lack of knowledge about the inner core material and due to the fact that the masonry material is not able to carry tensile stresses. A better understanding of both gravity load transfer mechanism and lateral resisting system of such structures is the key issue for a comprehensive structural analysis, interpretation of the analysis results and a proper intervention. Nowadays, with the development of computational methods, analyses of historical structures are mostly performed using Finite Element Analyses. Generating a finite element model of the structure require a good engineering experience to make a reasonable geometrical simplification of the complex geometry and a good assumption of unknown inner-core materials. 

Historical structures typically are more massive than contemporary structures and the structural resistance depends on the geometry of the structure, shape of the structural components and the characteristic strength and stiffness of the material used. Generally, the old foundation systems that support the historical structures are different from the current practice in terms of materials used, foundation-structure connections and the functionality. Ancient building masters had introduced special techniques to make the structure withstand the lateral forces and to control the underground water level and humidity. The engineering concepts in modern structures are not the same as of historical structures such as moment resisting system, diaphragm etc. The analysis method, strengthening, and other characteristics of such monuments should be investigated with special techniques. 

 When seismic strengthening of historical masonry structures is carried out, first of all, the characteristics of the structure should be examined in great detail and the structure should be known very well. Then; the tensile stresses that occur in the structure during the earthquake and the areas where these tensile stresses occur should be determined in a computer environment. Finally; the tensile forces formed in the structure should be taken with high-tech tensile elements that will be integrated into the structure. It is certain that; the strengthening method to be selected; should completely preserve the architectural and historical features of the structure.