Failure Analysis of Skewed Persian Brick Masonry Barrel Vaults: Experimental and Numerical Study

This study investigated the effect of skew angle on the failure load and structural behavior of Persian brick masonry barrel vaults using experimental and numerical methods. To this end, experiments were conducted to determine the mechanical properties of the materials and the vault's behavior under gravitational loads. Due to experimental and financial limitations, scaled models of materials and structures were employed. The gravitational loading was applied at a uniform rate and in two modes, symmetric (at mid-span) and asymmetric (at quarter-span). Then a numerical model developed using the nonlinear finite-element method was validated in ANSYS code by comparing the numerical and experimental results using the Willam-Warnke failure criterion. In addition, the effect of four skew angles and three vault dimension (span-to-depth) ratios on seven different geometries of Persian vaults, such as semicircular, pointed (raised, ordinary, and drop), and four-centered (raised, ordinary, and drop) was evaluated. In all modes, the results showed that the skew vault had a lower load-bearing capacity than the nonskew vault. In other words, the skewness of Persian brick vaults reduces their failure load. Moreover, the semicircular and drop pointed brick vaults demonstrated the highest sensitivity (54%) and lowest sensitivity (20.92%) to skew angle (at 45°) and nonskew modes compared to other Persian geometries, respectively. Also, the raised four-centered shape has the highest failure load in the symmetric and asymmetric modes.