Structural Analysis of Persian Historical Brick Masonry Minarets

Abstract

In this paper, the structural behavior of nine historical brick masonry minarets in Isfahan, which were built in the eleventh and twelfth centuries A.D., against weight, temperature, wind, and earthquakes is studied. A nonlinear three-dimensional FEM has been used. To investigate the effect of the central column and spiral staircase on the structural behavior, analyses have been performed for two cases: (1) the complete minaret, and (2) only the outer shell. The structural analysis of minarets under temperature changes shows that for certain inner and outer temperature differences, the minarets fail. Minarets do not fail because of the maximum wind velocity of Isfahan. All minarets fail when subjected to imposed earthquakes. By decreasing the minaret height or increasing the material strength, failure is delayed. Changing the failure criterion or damping ratio has little effect on the failure of the minarets.