NONLINEAR STATIC ANALYSIS OF MASONRY BUILDINGS THROUGH FIBRE-BASED CAPACITY MODELLING

Abstract

Seismic performance assessment of masonry buildings requires a nonlinear response analysis to achieve a reliable understanding of the possible effects of future earthquakes in terms of damage and losses. Equivalent frame (EF) modelling combined with nonlinear static procedures has been recognized as an efficient tool, which was validated in several studies through both experimental data and post-earthquake damage inspections. In this paper, a new macroelement based on a fibre formulation is implemented into a matrix analysis approach to build up a nonlinear EF model and to perform incremental static (push-over) analysis with response control. For each step of the analysis, the stiffness matrix of the structure is updated using the novel macroelement model, accounting for geometric and mechanical nonlinearities both in terms of flexural and shear behaviour. Floor systems are modelled with truss elements, the stiffness of which can be varied in order to consider either rigid or flexible floors. In addition, the capacity model can simulate different degrees of connection at wall intersections and can easily be adapted to consider structural elements made of reinforced concrete, steel, wood, or other materials. The capacity modelling procedure proposed in this study was first validated by simulating the in-plane lateral behaviour of a full-scale masonry wall with opening, and then, implemented to run pushover analysis of existing masonry buildings representative of those located in the Cam-pania region (southern Italy).