Blind bolted connections for steel hollow section columns in low rise structures

© 2011 Dr. Jessey LeeHollow sections have become increasingly popular in structural applications due to their superior load bearing capacity and natural aesthetic appeal. However, their use in low rise residential and commercial structures is hampered by the limited means of providing fully bolted site connections. This limitation can be overcome by using single sided or blind bolting. The merit of blind bolts is that installation requires access to one side only. This eliminates both the problem of lack of access and also the need to weld various accessories to the hollow sections. This research project focuses on the development of a range of connections to hollow sections using blind bolts. A series of tests have been performed to determine the behaviour of various configurations of blind bolted connections, exploring connections to the (i) face of the hollow section column, (ii) side wall of the column and (iii) front and back face of the column. This has resulted in the development of blind bolted moment connections for hollow section columns without concrete infill. Comprehensive three-dimensional finite element (FE) models have been developed to predict the behaviour of the developed connection with sufficient accuracy. Extensive parametric studies have been conducted to explore the effects of various parameters on the performance of these connections with specific focus on the stiffness. Simplified theoretical models based on the component model method proposed by Eurocode 3 have been formulated. These provide a quick and easy way for practising engineers to determine the stiffness of the proposed connections. Both the FE and theoretical models have been thoroughly validated against the experimental results. The successful development of the proposed blind bolted moment connections offers a convenient and efficient alternative for beam-to-hollow section column connections in low rise structures