Experimental and theoretical modeling for predicting bending moment capacity of T-head square-neck one-side bolted endplate to tube column connection

Abstract One-side bolting technology is expected to play an important role in the bolted connection between H-beam and Hollow Section Steel Column (HSSC). By evaluating the possible defects of the existing one-side bolts in terms of cost, installation, and mechanical properties based on plentiful reported studies, a new type of T-head Square-neck One-side Bolt (TSOB) was proposed, which has a simple construction, can adapt to the rough installation manners in the construction site, and no additional auxiliary tools are required. The bending performance of four T-head Square-neck One-side Bolted Connections (TSOBCs) for a beam to a HSSC and a Standard Double-sides Bolted Connection (SDBC) for comparison was experimentally studied, in which two arrangement patterns for the slotted bolt holes and two strengthening measures of stiffeners on the endplate and inner concrete in the HSSC was explored. The results show that the TSOBC with vertical bolt holes has nearly the same yield moment, and the horizontal bolt holes have more excellent post-yield performance, compared with the SDBC. Besides, three yield line patterns and an analytical model for calculating the bending bearing capacity of the HSSC and the concrete strengthened HSSC are proposed, respectively.