A simplified procedure for the seismic safety of large and slender rigid masonry blocks. (2016) - Casapulla, Claudia
This paper aims at finding the features of an artificial accelerogram which can be used to assess the seismic safety of large and slender rigid masonry blocks. The most important feature derives from a simple observation: well-known uncertainties on time variations of seismic actions imply that seismic risks analyses must be developed without privileging any detailed description of expected accelerograms. It follows that the best choice to build an artificial accelerogram is to represent it with sequences of instantaneous Dirac impulses and to look at its worst effects. A multiple impulse input is herein proposed, with impulses all applied right after the impact of the generic block on the ground. Intermediate impulses are then introduced to reduce the resonance effects and to cover a broad range of conditions. Approximate equations of block motion are proposed and numerical analyses are performed to highlight the most significant aspects of the proposed approach.