Bolt innovation to improve infrastructure strength and resilience

Image courtesy of Yusak Oktavianus, PhD candidate, dept. of infrastructure engineering.

A major research collaboration based around new uses for the Australian-designed ONESIDE™ bolt is aimed at creating more cost-efficient and resilient building systems.

The patented bolt technology was developed by Dr Saman Fernando at the Melbourne company Ajax Engineered Fasteners and has been adopted globally. It allows construction crews to bolt together steel structures – and to tighten the bolt – despite having access to just one side of structural joints. It was this technology that allowed the West Gate Bridge in Melbourne to be retrofitted to increase its load-bearing capacity.

Associate Professor Helen Goldsworthy at the University of Melbourne’s Department of Infrastructure Engineering leads the research team working with Ajax to develop new structural systems using ONESIDE™ bolts for residential and commercial buildings. These bolts can carry high clamping loads required by structural joints and allows bolting directly on to hollow members.

New construction systems have already been developed for low-rise residential buildings using ONESIDE™ bolts to connect hollow steel columns to the steel I-section beams.

Associate Professor Goldsworthy says in mid-rise commercial buildings with larger spans, hollow steel columns are commonly filled with concrete to add strength, particularly in Europe and earthquake-prone Japan.

Research has identified modifications that can provide further strengthening and stiffening of a steel frame through a headed stud extension that anchors the bolts to the concrete used to fill the steel columns.

Another modification being tested incorporates a replaceable component within the blind-bolted connection. “This acts like a fuse in the case of an earthquake and absorbs and dissipates energy that would otherwise compromise structural integrity,” Associate Professor Goldsworthy says.

The success of the latest modifications is based on extensive testing and numerical modelling of structural connection details. Collaborators with Dr Fernando and Associate Professor Goldsworthy include Professor Emad Gad from Swinburne University, Professor Brian Uy from the University of NSW and David Haynes from an Australian manufacturer and distributor of hollow steel tubes, Orrcon Steel.

More information: Associate Professor Helen Goldsworthy, +61 3 8344 7255,,