A semi-probabilistic approach for assessing material and model uncertainty in the out-of-plane response of URM structures

Abstract

A procedure tailored for a practical calibration of partial safety factors (PSF) related to input material properties is presented. The methodology addresses the propagation of material and model uncertainty through a FORM-based calibration, resulting in a noteworthy reduction in computation time compared to full probabilistic approaches. The novelty lies on the introduction of the Star Design with Central Point (SDCP) method for the computation of sensitivity coefficients and corresponding partial safety factors for material uncertainty. A calibration example is reported with reference to unreinforced masonry structures under out-of-plane failure. The effect of considering different geometries, failure modes, and modelling approaches is explored. A comparative analysis involving different approaches to propagate uncertainties emphasize the promising potential of the proposed procedure.