A Summary of Changes and Derivation of LRFD Bolt Design Provisions

Technical changes made in the 1994 RCSC LRFD Specification for Structural Joints Using ASTM A325 or A490 Bolts include such areas as shear-tension interaction for high-strength bolts in bearing connections and clear distance- based bolt bearing strength. In this paper, corresponding changes are proposed for the AISC LRFD Specification for Structural Steel Buildings and the supporting background information is summarized. Additionally, a change is proposed for the service-load slip resistance reduction factor for shear-tension interaction in slip-critical connections in both documents. Finally, a change made in 1993 AISC LRFD Specification Section J8.1 covering bearing strength of pins is documented.