Characterising the in-plane seismic performance of infill masonry

Abstract

Masonry infills, commonly found in frame buildings throughout Europe and other parts of the world, have performed poorly in past earthquakes, with infill damage endangering lives, causing disruption and significant monetary losses. To characterize the performance of masonry infills, commonly classified as non-structural elements, an extensive set of experimental test data is collected and examined in this work in order to develop fragility functions for the in plane performance of masonry infills. The collected data stems from testing conducted in Europe, the Middle East and the United States and includes solid and hollow clay brick or concrete block infills, constructed to be in contact within either reinforced concrete or steel framing. The results indicate that infill masonry can exhibit first signs of damage at drifts as low as 0.2% but may not suffer complete failure until drifts as high as 2.0%. Furthermore, it is shown that masonry fragility changes significantly according to the type of infill masonry. Subsequently, a short discussion is provided to highlight the potential use of the infill fragility information within non-linear analysis models of masonry infill. Finally, repair cost estimates for infills in Italy are computed using costing-manuals and are compared with cost estimates obtained through consultation with a number of Italian building contractors, with examination of both the median and dispersion in repair costs. It is anticipated that the results of this work will be particularly useful for advanced performance-based earthquake engineering assessments of buildings with masonry infill, providing new information on the in-plane fragility, repair costs and nonlinear modelling of masonry infills.

Developing collapse fragility curves for base‐isolated buildings

“…External masonry infills have been modeled with an equivalent compression-only diagonal strut, featuring a threelinear skeleton curve described by a "revised" Decanini model. 33 The influence of openings (windows or doors) in masonry infills has been taken into account reducing the strength and lateral stiffness of the panel with the reduction factors proposed in Delibera Giunta Regionale Umbria-Marche (DGR), 34 which depend on the dimensions of openings and their layout. Strength reductions of the order of 60% to 70%, in terms of forces, and 50% to 70%, in terms of drift, have been thus obtained.…”

Fragility functions for masonry infill walls with in‐plane loading

“…As expected, they found higher vulnerability in infill walls with openings. More recently, Sassun et al considered experimental results of 14 studies for a total of 50 specimens. They defined four damage states very similar to the ones presented by Cardone and Perrone, but differently from Cardone and Perrone, they only provided fragility curves for the whole sample without considering the effects due to the presence of openings.…”

“…Two notable exceptions are the recent works by Cardone and Perrone 14 and Sassun et al 15 , who, to the best of our knowledge, developed the first drift-based fragility functions for masonry infill walls. Cardone and Perrone gathered and analyzed the experimental results of 19 different studies for a total of 55 specimens.…”

Engineering Demand Parameters for the Definition of Collapse in Code Conforming Rc Buildings

“…These models describe the monotonic and cyclic behavior of the infill as a function of its mechanical and geometrical characteristics. [17,18] and the influence of openings was taken into account by using reduction factors for the panels' stiffness and ultimate strength, based on the work by Decanini et al(2014 [16]. The infills were modeled in Opensees with the Concrete01 material by fitting initial stiffness, peak strength, and ultimate deformation.…”