Issue 46

L.U. Argiento et alii, Frattura ed Integrità Strutturale, 46 (2018) 226-239; DOI: 10.3221/IGF-ESIS.46.21 226 Design of Civil Environmental Engineering Formulating the in-plane frictional resistances and collapse mechanisms for multi-storey masonry block walls L.U. Argiento, A. Maione, C. Casapulla University of Napoli Federico II, Department of Structures for Engineering and Architecture, Italy lucaumberto.argiento@unina.it arch.maione@gmail.com casacla@unina.it A BSTRACT . In this paper a macro-block model accounting for frictional resistances is presented to assess the lateral strength of a multi-storey masonry block wall. The kinematic approach of limit analysis is used to define the load factor causing the onset of rocking-sliding mechanism under in-plane horizontal loading. A dry frictional contact condition is assumed at the rigid block interfaces, according to the Coulomb's law with non-associated flow rule. The key aspect of the proposed approach is the introduction of a criterion to evaluate the contribution of the actual frictional resistances depending on the inclination angle of the crack line. An accurate assessment of the frictional resistances is also obtained by distinguishing two different contributions (the wall own weight and additional vertical loads) and their application points. Hence, a sensitivity analysis is performed with respect to the overloading condition, the friction coefficient, and geometrical parameters such as the shape ratios of the wall and of the unit block and the number of rows. The analytical results of the proposed model are also validated against results from other existing macro and micro-block modelling approaches in terms of load factor. The comparison confirms the reliability of the proposed model that allows, with similar results, great simplification of the computational effort with respect to micro-block models. K EYWORDS . Limit analysis; 3D macro-block model; Multi-storey masonry building; Rocking-sliding failure; Frictional resistances. Citation: Argiento, L.U, Maione, A., Casapulla, C., Formulating the in-plane frictional resistances and collapse mechanisms for multi-storey masonry block walls, Frattura ed Integrità Strutturale, 46 (2018) 226-239. Received: 29.07.2018 Accepted: 26.08.2018 Published: 01.10.2018 Copyright: © 2018 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION he seismic damages suffered by unreinforced masonry block structures are often due to partial collapses with loss of equilibrium of walls or portions of them, while material failure rarely occurs. Experimental tests carried out since ’80s of the last century on brickwork samples [1-3] have proved that the mechanical performance of such a T