Retrofit Of The Masonry Minaret Of Historical Mosque With Frp: A Case Study

Abstract

This paper deals with the seismic behavior and a new retrofit strategy of block masonry minaret of a historical mosque in Istanbul. Today, it is a well known fact that earthquakes are one of the most important problems that Turkey and many other countries have to deal with. There are large number of historical mosques and large number of minarets which were built since older times. Since Turkey located in highly seismic zone, the probable damage to the masonry minarets should be determined in advance and necessary precautions should be taken. The problem of seismic protection of the historical heritages have been always challenging for engineers in terms of analyzing and retrofitting of these structures due to extremely complex behavior of the material used in the construction. To achieve this objective, the minaret of historical mosque in Istanbul is chosen as a case and 3D finite element model of structure have been prepared to obtain plausible lateral displacements, probable cracking zones and failure modes under earthquake loads. The problem becomes more complex when the dynamic analyses are also involved. After the developments in the dynamic testing of structures and computational methods in structural analysis, studies in this field have led some significant results about the mechanical behavior of the old buildings. These types of studies are essential not only in protection/retrofit viewpoint but also assessment of similar historical structures. Within this outline, the dynamic behavior of old masonry minarets, which usually exhibit vulnerable behavior under seismic loading, was investigated. The results obtained from the numerical analysis have shown that the possible failure zones under seismic action can be predicted quite accurately with reasonable results, and can be used in the preservation of these minarets to guarantee their stability in case of an earthquake by reinforcing those parts which will undergo the greatest damage (usually located at the base and the lower part of the minaret). Furthermore, the analyses are performed by using fiber reinforced polymer (FRP) sheets wrapped around these critical cross sections and the results are promising in terms of seismic protection of these heritages. Preservation of cultural heritage for the future generations is indispensable for every country in the modern world. Therefore, paying enough attention to protection of historical structures is one of the most important issues in highly-seismic developing countries.