Examination of the Damage Limits of a Historical Mosque, Konya Sultan Selim Mosque Example

Abstract

The idealized global base shear force-top displacement relationship of the mosque was determined by drawing a backbone curve that bounds the force-displacement point values (F, D) representing critical actions, such as maximum force, maximum displacement, cyclic unloading paths, initiation and end of strength and stiffness reduction on the hysteresis curves from time-history analysis. Two different material parameters were employed in the analyses to account for the variation in material properties. Values from the linear response region were also taken to clarify the initial stiffness. In addition, the selected (F, D) points include almost all the values in the cycle in which the mosque is considered to have collapsed. Failure was decided by evaluating the load-deformation hysteresis curves and strain values (damage) on the finite element model. The backbone curve was idealized in three-linear form and damage limits of historical Sultan Selim mosque were defined on this curve (Figure A).Purpose:This paper presents the details of the seismic performance evaluation of the historical Konya Karapinar Sultan Selim mosque. The effect of variation in material properties on the seismic performance of historical mosques is examined by employing possible lower and upper bound values of modulus of elasticity (E). It is aimed to determine the reliability of existing damage limits on masonry structures.Theory and Methods: A detailed finite element model of the historical Konya Sultan Selim mosque was created. For modulus of elasticity E=200fc and E=750fc were assigned to finite element models. Nonlinear time-history analyzes were carried out under five different ground motions. The force-drift ratio curves of the mosque were idealized as defined in Figure A. The damage limits for each performance levels of the mosque were determined.Results: The calculated drift ratio limits were found to be lower than the limits recommended in the codes. The results of structural analyses available in the literature also indicate to lower displacement capacity of masonry structures than the collapse limits given in codes. This indicates that existing code limits provides unsafe prediction of seismic performance of masonry mosque. Conclusion: The proposed approach in this study should be applied on different historical mosques to determine more generalized damage limits. It is also noted that the seismic behavior and damage limits of historical mosques are different from other masonry structures.