ASSESSMENT OF AMERICAN BLOCK SHEAR LOAD-CAPACITY PREDICTIONS

Block shear is known to be a potential failure mode for several differ ent types of connections. In this study,failure loads determined by ex perimental block shear tests performed in North America are compared w ith the corresponding capacities predicted by the current American Ins titute of Steel Construction Load and Resistance Factor Design and All owable Stress Design Specifications. The two different design procedur es are shown to provide a reasonable level of accuracy, although they both exhibit a fairly wide variation in experimental-to-predicted load capacity ratios. In an effort to identify and in turn, attempt to qua ntify the influence of additional connection parameters that may influ ence block shear behavior, several failure load design equations are d eveloped to fit the experimental data. It is shown that (1) the variat ion in the capacity ratios can be significantly reduced by incorporati ng the 'aspect ratio' of the block and the in-plane load eccentricity measured to the bolt line, and (2) failure loads can be predicted with equal accuracy using either the material yield strength or the ultima te strength.