Experimental characterization of the out-of-plane performance of regular stone masonry walls, including test setups and axial load influence

Abstract

Stone masonry is one of the oldest and most worldwide used building techniques. Nevertheless, the structural response of masonry structures is complex and the effective knowledge about their mechanical behaviour is still limited. This fact is particularly notorious when dealing with the description of their out-of-plane behaviour under horizontal loadings, as is the case of the earthquake action. In this context, this paper describes an experimental program, conducted in laboratory environment, aiming at characterizing the out-of-plane behaviour of traditional unreinforced stone masonry walls. In the scope of this campaign, six full-scale sacco stone masonry specimens were fully characterised regarding their most important mechanic, geometric and dynamic features and were tested resorting to two different loading techniques under three distinct vertical pre-compression states; three of the specimens were subjected to an out-of-plane surface load by means of a system of airbags and the remaining were subjected to an out-of-plane horizontal line-load at the top. From the experiments it was possible to observe that both test setups were able to globally mobilize the out-of-plane response of the walls, which 123Bull Earthquake Eng (2015) 13:2667-2692 DOI 10.1007 presented substantial displacement capacity, with ratios of ultimate displacement to the wall thickness ranging between 26 and 45 %, as well as good energy dissipation capacity. Finally, very interesting results were also obtained from a simple analytical model used herein to compute a set of experimental-based ratios, namely between the maximum stability displacement and the wall thickness for which a mean value of about 60 % was found.

A numerical study on the cumulative out‐of‐plane damage to church masonry façades due to a sequence of strong ground motions

“…The mechanical parameters of the materials have been selected with the aim of covering a broad and meaningful set of realistic situations rather than to analyze the response of 2 masonry bonds specifically related to the church façades selected for the present research. Considering that the external layers of the 2 masonry typologies can be described as “squared limestone blocks” for bond‐texture (1) and “regular clay bricks” for bond‐texture (2), the mechanical properties have been assigned in agreement with the recent literature, as well as with the Italian building code for existing masonry building (eg, Ministero delle Infrastrutture e dei Trasporti, table C8A.2.1 and C8A.2.2). The internal layer has been considered as the weakest part, usually made by rubble stones and broken bricks.…”

“…[25][26][27][28] For the purposes of the present study, the numerical modelling should be efficient, to perform full nonlinear dynamic analyses with an acceptable computational effort, but not simplistic, since the damage response of the building materials, in the context of the composite nature of the 3-leaf masonry walls, should be properly included. [29][30][31][32] Special attention should be devoted to the definition of a reasonable nonlinear material response compatible with the experimental evidence as well as with analytical and microstructure numerical modelling, 16,33,34 by accounting for the static vertical compression, the 3-leaf bond effects, the internal friction, and the progression of damage with hysteretic dissipation.…”

Design of masonry infill walls with sliding joints for earthquake structural damage control

“…The application of a uniform out-of-plane loading pretends (as was observed) to globally mobilize the out-of-plane response of the IM wall. In the literature similar out-of-plane load distribution adopted by other authors can be found (Griffith et al, 2007, Ferreira et al, 2015. This reaction structure is composed by five vertical and four horizontal alignments of rigidly connected steel bars, in front of which a vertical wooden platform is placed to resist the airbag pressure and transfer it to the steel reacting grid elements.…”

Nonlinear Dynamic Analysis for Safety Assessment of Heritage Buildings: Church of Santa Maria de Belém

“…A wide range of sophisticated mechanical models have been developed to predict the nonlinear behavior of masonry material both in tension (low tensile capacity with consequent cracking phenomena) and compression, including individual failure and damage mechanisms (Ferreira et al 2015a). Unfortunately, some of these models are rather difficult to apply to the 3D analysis of complex structural systems, not only because of the large number of parameters involved in the definition and updating of the mechanical model but also because of the number of DoF required to mesh the structure .…”