Safety Factor of Masonry Arches under Gravity Loads

In the present paper, a procedure is presented for the evaluation of the safety factor and the limit conditions of masonry arches subject to gravity loadings. The proposed procedure can be considered an extension of Heyman’s method for determining the geometrical safety factor. At variance with Heyman’s method, herein, the analysis of the static safety condition for the arch is performed by means of modified kinematic configurations of the arch obtained by encompassing settlements at the arch constraints. Furthermore, the procedure allows the identification of the critical locations of the hinges in the arch at the limit conditions. Moreover, the present procedure allows the determination of the geometrical vertical displacement that the crown of the arch can accommodate at the safety limit conditions. Finally, the proposed procedure is applied to a real case in order to show its effectiveness. Numerical results are reported and commented on in order to clarify the application of the proposed procedure for the definition of the safety factor of the arched structure and the evaluation of the critical geometrical configuration compatible with the limit conditions of the arch.