Mitigating seismic risks in historical masonry: An example project

Protection of cultural heritage buildings against strong seismic events is one of the most challenging tasks modern engineers are called to tackle. Masonry structures are complex with regional and historical diversities rendering extremely difficult defining generalized rules. A holistic approach that involves interdisciplinary collaboration and a full package of engineering from monitoring to testing is a necessity. The sources for assessment, strengthening, and preservation are not enough for the entire inventory of heritage buildings, thus there always exists need for conducting risk studies to estimate the seismic risk these structures are exposed to. The main ingredient of seismic risk studies is the definition of the structural limit states, which is one of the most challenging topics since the historical structures rarely possess similarities among them while their response is characterized by complex interaction of structural components. This paper presents a scientific project funded to contribute to the mitigation of seismic risk in the historical peninsula of Istanbul where Eastern Rome, Byzantine, and Ottoman structures populate almost every street. A complete approach has been followed in the project, the main activities of which consist of creating a wide strong ground motion and ambient vibration network, building and testing large-scale specimens to define limit states of the masonry heritage structures and combining the monitoring an testing findings with analytical modelling tools. The project resulted in a master plan in which steps to be taken to protect the existing heritage buildings in the historical peninsula of Istanbul is proposed and discussed.