Effect of soil properties on the seismic damage assessment of historical masonry minaret-soil interaction systems

The interaction between soil and structure plays a crucial role on accurate determination of structures' seismic behavior. The assumption of fixed base structure has been commonly used in traditional design works, and the interaction between soil and structure is thus often neglected. In addition, historical masonry structures particularly built on elastic soil media may be significantly affected seismic behavior of the structure under earthquakes. In this research, the damage distribution on a historical masonry minaret is numerically investigated under horizontal earthquake ground motion. Alaca Mosque minaret was built in 1271 in Bolvadin district of Afyon province. The historical masonry minaret was chosen as the subject of the study. Nonlinear seismic time history analyses were conducted for fixed-based and different soil properties under horizontal earthquake ground motion. The horizontal (East-West) component acceleration records of Dinar earthquake (Mw = 6.1) that took place on October 10, 1995, were used during the analyses. Maximum displacement, maximum/minimum principal stresses, and damage ratios were determined by nonlinear analyses performed considering fixed base and soil-structure interaction. The analysis results showed that soil-structure interaction had significant effect on the structural behavior of the minaret, such that, the minaret that was expected to get damage in the case of fixed base did not get any damage when soil-structure interaction was considered.