Enabling the design of giant, slender structures

Daniel Powell from Arup will be giving his inaugural RAEng Visiting Professor lecture as part of the Civil Engineering seminar series. Daniel joined the group this year through the Royal Academy of Engineering Visiting Professor scheme. The lecture is titled “Enabling the design of giant, slender structures” and in it Daniel will draw from his extensive experience to talk to us about the challenges encountered in the design of some iconic, highly-slender structures, including “The Scalpel” in London and the US Air Force Memorial in Arlington.

Enabling the design of giant, slender structures
Inaugural RAEng Visiting Professor lecture
Daniel Powell, Arup

This lecture will provide insights into the challenges encountered in the design of a collection of high-profile, highly slender structures as well as the methods that made them possible, in particular the development of novel, bespoke damping systems.

Examples will include: the world’s tallest statue in Gujarat; the ArcelorMittal Orbit; and, in greater depth, ‘The Scalpel’ in London and the US Air Force Memorial.

‘The Scalpel’ in the City of London is a 190m tower completed in 2018. During design, savings of around 2,500te of structural steel were realised by introducing large, viscous dampers along the load-path of a mega-brace. These significantly reduce the wind induced global loads. The talk will expand on the technical and practical challenges in developing this pioneering approach for improving the efficiency of high-rise buildings.

The US Air Force Memorial comprises three stainless steel spikes which arc outwards to evoke an image of jet engines in a ‘bomb burst’ manoeuvre. As structural designers, we were challenged to maximise the slenderness of this giant sculpture which has triangular sections highly vulnerable to the aerodynamic instability galloping. This was achieved through the installation of ‘ball-in-box’ impact dampers - 700kg steel spheres free to roll and impact inside padded boxes within the spires.

The talk will summarise the analysis and design process used to develop these highly non-linear devices.

Please address any questions about the seminar to orestis.adamidis@eng.ox.ac.uk