ABSTRACT
Recent strong earthquakes produced heavy structural damages to existing unreinforced masonry (URM) buildings, particularly in the case of historic urban centres such as L’Aquila (2009) and Amatrice (2016). Spatially-distributed damages at urban-to-regional scale, as well as the need to speed up the recovery process, have motivated an extensive use of fabric-reinforced cementitious matrix (FRCM) systems for external retrofitting of URM buildings. This has significantly motivated the development of ad-hoc guidelines for a mechanics-based design of FRCM retrofitting systems. In this paper, the authors present a novel flexural capacity model for incremental static analysis of URM walls subjected to in-plane lateral loading. The formulation makes use of a fibre-based approach that explicitly accounts for geometric and mechanical nonlinearity sources at sectional level. Capacity modelling was carried out using data sets available in the 2019 Italian building code commentary and experimental review studies. The output of this study is focused on moment–curvature diagrams remarking a number of performance limit states. This study attempts to move beyond the classical strength-based verification formats implemented in current guidelines for the ultimate limit state. The proposed capacity model allows evaluating the evolution of flexural behaviour as cracking and crushing propagate throughout the URM-FRCM cross section.
