Seismic Analysis and Retrofitting With FRP of an Old Masonry Clock Tower

Abstract

The seismic analysis of old masonry structures represents an important issue nowadays. Many researches have been developed to highlight on this important subject and how to apply retrofitting strategies appropriate for this kind of problems. This paper deals with the numerical seismic analysis and the benefit of the FRP retrofitting method on the seismic behavior of an old masonry clock tower located in Tripoli. Lebanon is a country with a high seismicity and is well known by its historical monuments and sites indeed. The chosen structure, called Al Tall clock tower, is one of the most significant monuments of Tripoli and was built by the Otto-mans in 1902. Therefore, a three dimensional finite element model is used to assess the seismic vulnerability of the structure by using the non-linear time history analysis first. Then, a pushover analysis was carried out and both results were compared. The obtained deformed shape and stress maps were used to highlight on the failure modes and the weak zones within the tower. The results exhibit the vulnerable behavior of the structure and the developed damaged zones along its height. Furthermore, a numerical model of the structure strengthened using fiber reinforced polymer (FRP) sheets wrapped around these critical zones is created. The analyses showed an improvement of the tower lateral strength and are promising in terms of reducing the seismic vulnerability of the old masonry monuments.