Dr Lewis Gooch

This paper presents the results of an extensive set of material characterisation tests performed on unreinforced clay brick masonry. The results of these experiments allow for the estimation of relationships between the measured material parameters. This study considers the relationships of flexural tensile bond strength to direct tensile bond strength, flexural to direct tensile strength of fired clay brick masonry units, and flexural tensile to shear bond strength. A mean ratio of flexural tensile bond strength to direct tensile bond strength of 2.06 and a COV of 31.5% were determined. For the flexural to direct tensile strength of fired clay brick masonry units, a mean ratio of 1.29 with a COV of 14.7% was estimated. Finally, considering the ratio of the shear bond to flexural tensile bond strengths, a mean ratio of 1.34 with a COV of 28.4% was found. In addition to these relationships, suitable probabilistic models were determined to describe the relationship between the flexural and direct tensile bond strengths, and the flexural tensile and shear bond strengths. These results may be used in future studies of URM structures, in particular finite element modelling and stochastic analyses of masonry.

This paper develops a modelling strategy for the finite element analysis of perforated (arched) unreinforced masonry walls subjected to in-plane shear loading. An experimental baseline was used to facilitate an accurate calibration and assessment of the chosen modelling strategy. This study provides the procedure and the results relevant to a stochastic assessment of unreinforced masonry shear walls. These results may be used in future studies of the reliability of these structures and may be applied in the calibration of reliability-based design practices. Utilising a two-dimensional micro-modelling approach, the capacity of a monotonic loading scheme to capture the envelope of a cyclically applied load was examined. It was found that, while the elastic stiffness of the laboratory specimens was overestimated by the finite element models, the peak load and global response was accurately recreated by the monotonically loaded models. Once the applicability of this procedure had been established, a series of spatially variable stochastic finite element analyses were created by considering the stochastic properties of key material parameters. These analyses were able to estimate the mean load resistance of the experimentally tested walls with a greater accuracy than a deterministic model. Furthermore, these analyses produced an accurate estimate of the variability of shear capacity of and the observed damage to the laboratory specimens. Due to the fact that the tested walls failed almost exclusively in a rocking mode, a failure mechanism highly dependent upon the structures¿ geometry, the variability of the peak strength was minimal. However, the observed damage and presence of some sliding and stepped cracking indicates that the proposed methodology is likely to capture more variable and unstable failure modes in shear walls with a smaller height-to-length ratio or those more highly confined.