Event archive

Event Organiser: The British Geotechnical Association

The 59th Rankine Lecture: Benefits of Unconventional Seismic Foundation Design, London

  • Lecture
  • London
  • 20 March 2019
  • 17:30 - 19:00
The 59th Rankine Lecture: Benefits of Unconventional Seismic Foundation Design, London

About this event

Current seismic geotechnical practice has embraced concepts inspired by pseudo-static thinking and force-based methodologies. The result is often over-designed foundations that, in addition to being uneconomical and difficult to implement, might unexpectedly lead to poor technical performance of foundation–structure systems.

The benefits of drastically changing the established philosophy in seismic foundation design will be explored, emphasising the “foundation rocking and soil failure” of tall slender structures, the foundations of which were deliberately under-designed to ensure that, during strong shaking, substantially nonlinear and inelastic soil-foundation interaction takes place ― uplifting of footing from the supporting soil, along with mobilisation of bearing-capacity failure mechanisms in the soil.

Thanks to the kinematic nature of seismic shaking, allowing such unconventional response limits the accelerations transmitted up into the super-structure, hence it reduces the inertia loading which “returns back” onto the foundation in the form of overturning moments and shear forces. Owing to its cyclic nature, seismic response generates a significant amount of damping in the soil, while exceedance of the ultimate capacity acts (only) momentarily and alternatingly. The two phenomena contribute towards decreased response intensity and acceptable levels of residual deformations (displacements and rotations). Deformations are further diminished by the beneficial contribution of gravity to re-centring of the foundation.

Physical experiments, analyses, and field observations, involving a variety of structural systems and foundations, will illustrate the technical advantages of such unconventional designs. Analysis of two historic seismic case histories, involving failure of bridge piers and overturning of buildings, will further demonstrate the potential benefits (as well as the limitations) of this new paradigm in seismic soil–foundation–structure interaction.

Pre-lecture refreshments will be served at 17:00 hours.

The lecture will be broadcast live and the link made available via the BGA website at https://www.britishgeotech.org/events/173-bga-59th-rankine-lecture prior to the event.

Please note: Advance Registration is not required

Speakers

Professor George Gazetas

National Technical University of Athens

George Gazetas

George has been Professor of Geotechnical Engineering at the National Technical University of Athens for 30 years, following an academic career in the US, where he taught at SUNY-Buffalo, Rensselaer (RPI), and Case Western Reserve University. His main research interests have focused on the dynamic response of footings, piles and caissons; the seismic response of earth dams and quay-walls; soil amplification of seismic waves; and soil–structure interaction problems.

Much of his research has been inspired by observations after destructive earthquakes. An active writer and teacher, he has been a consultant on a variety of (mainly dynamic) geotechnical problems. The recipient of prestigious awards for his research contributions, he has given the Coulomb (2009) and Ishihara (2013) Lectures, and received the Excellence in University Teaching Award in Greece (2015).

Event venue

The Great Hall, Sherfield Building
Imperial College
Exhibition Road
London
London SW7 2AZ
United Kingdom

For more information please contact:

Shelagh Fleming

e: [email protected]

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