Multi-storey walls with openings, composed by wall piers and spandrels, represent the main resistant structural components of a masonry building. The in-plane seismic forces are countered by means of their weights, which oppose to the action of the horizontal forces. The behaviour of masonry constructions results to be very far from the one characterizing ductile structures, because of the lack of energy dissipation during the deformation. Masonry constructions endeavour in fact to elude the seismic action, activating a rocking motion rather than deforming with doubtful dissipating mechanisms. A strength resource of masonry structures, properly reinforced in order to avoid early local failures, consists in exhibiting rocking behaviour, until a failure condition is attained. Aim of the paper is to investigate the dynamic behaviour of masonry multi-storey walls, according to Housner's studies and properly introducing the effect of diagonal cracks, shown by typical post-earthquake cracking patterns. Cracks start from the toe of the wall piers, developing along a diagonal direction and identifying a masonry volume that remains ineffective during the development of the mechanism, without taking part with its weight to the opposing action against the overturning. Starting from the evaluation of the incipient rocking acceleration of the system, in presence of cracking of the masonry wall piers, the free and forced motions of the wall are examined. A simple constant horizontal acceleration impulse of given duration has been considered to represent schematically the seismic action. An ad hoc energy dissipation model is also specifically implemented, according to the classical Housner's approach.
Como, M., Di Carlo, F. (2017). Rocking of cracked masonry walls under constant impulse acceleration. In AIMETA 2017 - Proceedings of the 23rd Conference of the Italian Association of Theoretical and Applied Mechanics (pp.1379-1401). Centro Servizi d'Ateneo S.r.l..
Rocking of cracked masonry walls under constant impulse acceleration
Como M.;Di Carlo F.
2017-01-01
Abstract
Multi-storey walls with openings, composed by wall piers and spandrels, represent the main resistant structural components of a masonry building. The in-plane seismic forces are countered by means of their weights, which oppose to the action of the horizontal forces. The behaviour of masonry constructions results to be very far from the one characterizing ductile structures, because of the lack of energy dissipation during the deformation. Masonry constructions endeavour in fact to elude the seismic action, activating a rocking motion rather than deforming with doubtful dissipating mechanisms. A strength resource of masonry structures, properly reinforced in order to avoid early local failures, consists in exhibiting rocking behaviour, until a failure condition is attained. Aim of the paper is to investigate the dynamic behaviour of masonry multi-storey walls, according to Housner's studies and properly introducing the effect of diagonal cracks, shown by typical post-earthquake cracking patterns. Cracks start from the toe of the wall piers, developing along a diagonal direction and identifying a masonry volume that remains ineffective during the development of the mechanism, without taking part with its weight to the opposing action against the overturning. Starting from the evaluation of the incipient rocking acceleration of the system, in presence of cracking of the masonry wall piers, the free and forced motions of the wall are examined. A simple constant horizontal acceleration impulse of given duration has been considered to represent schematically the seismic action. An ad hoc energy dissipation model is also specifically implemented, according to the classical Housner's approach.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.