Structural Steel Joints with Bolts in Threaded Holes

Abstract

The application of tubular columns in steel structures offers many advantages. However, this potential has not been fully utilized due to a lack of access for the installation of standard bolts in end-plate beam-to-column joints. Blind bolts are an alternative way of connecting the beam end-plate to hollow section column, for they can be installed and tightened from outside of the column. Standard high strength bolts can be directly screwed into the threaded hole tapped in the column hole wall. Bolts in threaded holes (BTH)-use threads on the bolt hole wall as an anchorage instead of nuts used in standard bolt assemblies. Provisions regarding BTH can be found in the draft version of new Eurocode 3, Part 1-8, including the definition of minimum thread engagement lengths. Parametric study of beam-to-tubular column joint with extended end-plate was conducted in order to analyse the influence of BTH and specific failure modes on overall joint resistance. Minimum thread engagement length limitations were checked for all considered combinations of parameters, and based on these results, an overview of the general applicability of bolts in threaded holes was gained.