This paper aims to evaluate the in-plane shear strength expressions of partially
grouted masonry (PGM) walls in four international design codes, including masonry design codes
of practice in the United States, New Zealand, Canada and Australia. Experimental results of 89
partially grouted masonry walls that displayed shear failure were collected from published research.
The shear strengths of the walls in the database were calculated using the different code equations
and compared with those from the experimental results. In addition, the parameters that infl uence
the shear strength of the walls, including masonry tensile strength, level of axial compressive stress,
wall aspect ratio, and the amount and spacing of vertical and horizontal reinforcement are studied.
Both univariate and multivariate regression analysis have been employed to investigate the effect
of each parameter on the accuracy of the code shear strength predictions. This study illustrates
poor correlation between code predictions and test results, indicating that current codes are unable
to predict the shear strength of PGM walls. In some cases the code shear strength predictions are
three to four times the experimentally measured shear strength, indicating that modifi cations are
needed as the current provisions are unconservative. An equation is therefore proposed which better
estimates the strength of PGM walls.