Seismic Assessment of a Cultural Heritage Minaret in Cairo

Dealing with cultural heritage is a sensitive process since each monument has its history, story, conditions, and scharacter. In this work, we assessed and evaluated the seismic vulnerability of a well-preserved cultural heritage structure that is the minaret of the Madrasa of the Princess Tatar al-Higaziya in Cairo. We selected the minaret site's input seismic source based on a physics-based ground motion simulation named multi-scenario seismic input (MCSI). This seismic source was used for the assessment of the dynamic behaviour of the minaret. A detailed numerical model of the minaret was developed in SAP2000. An initial bi-directional response spectrum analysis was performed on the minaret, considering the coefficient of subgrade reaction of soil. Both a record of the 1992 Cairo earthquake and synthetic seismograms were used. The calculations confirm no damage in the case of the 1992 earthquake while, in the worst-case scenario, the minaret could suffer significant tensile stresses that exceed the tensile strength of the limestone material. Results denote enormous cracking and even crushing in the minaret body, particularly at the base and at a geometry transition zone right above the base. Furthermore, the tensile stresses’ level predicts collapse or severe minaret damage under the C-MCSI-50% bidirectional response spectrum load. Results were confirmed by time-history analyses performed on the model. The results emphasize the importance of predicting the behaviour of heritage and historical structures against strong earthquakes, especially for those that share similar structural characteristics (e.g., height, construction time and materials) with our case study historical structure.