Unified block shear equation for achieving consistent reliability

Abstract Equations in design standards for block shear vary widely and, when used for different types of connections, they provide significantly inconsistent levels of safety. In many cases reported in the literature, recommended changes are intended to address a specific deficiency without assessing the overall impact on design in a broader sense. Moreover, a reliability study is required to fully assess the level and consistency of resulting safety indices. To resolve these shortcomings and inconsistencies, a database of 205 block shear tests on gusset plates, angles, tees, and coped beams from 17 different research programs was compiled and a reliability study conducted. From this study, as well as from the failure modes observed in the tests, a unified block shear equation is proposed that provides much more consistent test-to-predicted block shear capacity ratios over a wide variety of connection types, geometries, and steel grades. The unified equation also results in consistent safety indices for gusset plates, angles, tees, and coped beams with either one or two lines of bolts, a goal that is not achieved by other methods available. A resistance factor is recommended for design that will achieve an appropriate level of safety.