Global drift ratio limits for historical masonry mosques.

Drift-based performance limits are commonly used in seismic performance assessment. However, many studies have indicated substantial considerations for the displacement-based approach when applied to historical masonry structures. Variability in failure mechanisms, geometrical uncertainties in structural form, loading and boundary conditions and incompatible performance damage limits among codes can be examples to such considerations. This article discusses the reliability of the drift limits recommended in different codes and guidelines by comparing drift values obtained from the time-history and pushover analyses of 11 historical masonry mosques. The effect of material stiffness on the drift capacity of the structures was evaluated in regards to possible lower and upper value of modulus of elasticity in masonry elements. It was determined that the drift values proposed in the codes and guidelines can lead to incorrect and unsafe seismic evaluation on architectural heritage. For historical masonry mosques, global drift ratio values between 0.01–0.07, 0.06–0.25, 0.08–0.45% are recommended for damage limitation, significant damage and near collapse limit states, respectively. Simplified equations incorporating dimensional and mechanical properties are proposed to determine the drift ratio limits of historical mosques. [ABSTRACT FROM AUTHOR]