Experimental Evaluation of Shear Behavior of Stone Masonry Wall

Abstract

The evaluation of the shear behavior of masonry walls is a first fundamental step for the assessment of existing masonry structures in seismic zones. However, due to the complexity of modelling experimental behavior and the wide variety of masonry types characterizing historical structures, the definition of masonry’s mechanical behavior is still a critical issue. Since the possibility to perform in situ tests is very limited and often conflicting with the needs of preservation, the characterization of shear masonry behavior is generally based on reference values of mechanical properties provided in modern structural codes for recurrent masonry categories. In the paper, a combined test procedure for the experimental characterization of masonry mechanical parameters and the assessment of the shear behavior of masonry walls is presented together with the experimental results obtained on three stone masonry walls. The procedure consists of a combination of three different in situ tests to be performed on the investigated wall. First, a single flat jack test is executed to derive the normal compressive stress acting on the wall. Then a double flat jack test is carried out to estimate the elastic modulus. Finally, the proposed shear test is performed to derive the capacity curve and to estimate the shear modulus and the shear strength. The first results obtained in the experimental campaign carried out by the authors confirm the capability of the proposed methodology to assess the masonry mechanical parameters, reducing the uncertainty affecting the definition of capacity curves of walls and consequently the evaluation of seismic vulnerability of the investigated buildings.

Strength Parameters of Clay Brick Walls with Various Directions of Force

“…An example of masonry loaded at different angles to the bed joints are walls subjected to seismic actions. The evaluation of the shear behavior of masonry walls is a fundamental step for the assessment of masonry in seismic zones [ 11 , 12 ]. Under lateral forces, the low tensile strength generally leads to local or global failure modes, the latter related to shear or flexural mechanisms [ 13 ].…”

“…The latest works in the field of research and modeling of masonry structures concern the influence of the value of the modulus of elasticity and Poisson ratio outside the range of 33% of the ultimate stress on the shear behavior of masonry walls. Nonlinear static analyses are commonly adopted for the evaluation of seismic performance [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. Research on that subject has been presented by Laurenco et al [ 14 ] with a yield criterion that includes different strengths along each material axis.…”

“…Celano et al in [ 15 ] presented research on the in-plane resistance of masonry walls by means of two modeling approaches: a finite element model and a discrete macro-element model with the use of non-linear analyses. Beconcini et al in [ 12 ] presented a combined test procedure for the experimental characterization of masonry mechanical parameters and the assessment of the shear behavior of masonry walls.…”

Environmental and Economic Impact of Retrofitting Techniques to Prevent Out-of-Plane Failure Modes of Unreinforced Masonry Buildings

“…Integrated interventions capable of counteracting the OOP mechanisms of masonry buildings can be numerous. Among typical strengthening measures, one can cite tierods [24,31], a traditional retrofitting measure for preventing OOP failure modes, CFRP and GFRP strips [43] vertically placed GFRP nets, ferro-cement, strength anchors [32,33], trusslike steel strips reinforcement [44], or rolls of fiber fabrics inserted in the masonry courses by using indent technique [5]. However, when the objective of the intervention is not only to improve the structural performance but also the thermal behavior of the building, these interventions are often associated with the implementation of energy-saving measures, such as the application of insulating panels.…”

New Frontiers of Composites Applications in Heritage Buildings: Repair of Exposed Masonry of St. Nicola Church in Pisa

“…Specific examples of the application of the aforesaid procedure to historical structures are discussed in [18][19][20][21][22], also considering the effects of uncertainties [23,24], while extensive discussions about the evaluation of the statistical properties of the mechanical properties of building materials are reported in [25][26][27], where special methods are proposed to derive the main statistical parameters of the relevant mechanical properties of building materials of existing constructions, based on objective, blind, cluster analyses of available databases of in situ, and laboratory test results, assuming suitable probabilistic mixture models. The rationale of these special methods is that the mechanical properties of the building materials of coeval structures, characterized by similar typology, location, workmanship, and structural scheme, are described by comparable statistical parameters.…”