Seismic Performance and Recommendation of Structural Intervention on Masonry Heritage Clock Towers: Representative Examples in Bosnia and Herzegovina

The paper deals with selected examples of clock towers in Bosnia and Herzegovina, representing high masonry heritage buildings made of stone, and explains the approach used in their preservation and restoration. The aim of this paper is to present a specific method of conservation used on stone structures. Three clock towers from Bosnia and Herzegovina were selected as representative examples: Sarajevo Clock Tower from the 16th century is an example of well-preserved building; The Clock Tower in Gradačac, the youngest building of this type in Bosnia and Herzegovina, is in poor structural conditions and in danger of collapsing; The Clock Tower in Banja Luka, the first clock tower in Bosnia and Herzegovina, was demolished in 1993 but the reconstruction project is planned for the current year. This paper addresses the structural properties of masonry clock tower from the Ottoman period, with special attention to preservation, analysis and strengthening. These tasks are still a challenge for masonry practitioners even if significant advances in research have been made in the last decades. The dynamic behavior of the historical buildings is usually analyzed to design repair intervention solutions and retrofitting. The structural behavior is analyzed using FEM modeling to examine how far the structural defects endanger the stability of the tower. The soil properties problem under the tower has been considered. Simplified yet effective procedures have been used as well. Results of the analysis have confirmed insufficient performance of the structure under horizontal action and the need for improvement.