The British Geotechnical Association (BGA) is the principal
association for geotechnical engineers in the United Kingdom.

The 60th Rankine Lecture

BGA Meeting
  • 16.03.2022
  • 17:30 - 19:30
  • The Great Hall, Sherfield Building, Imperial College London, Exhibition Road, SW7 2AZ
  • Event Type: BGA Meeting
  • Download to Calendar
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The 60th Rankine Lecture: The Unusual and the Unexpected in Geotechnical Engineering: Observation – Analogy – Experiment

by

Professor Stephan Jefferis of Environmental Geotechnics Limited

16th Mar 2022 17:30 hours

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

Event Information

The British Geotechnical Association (BGA) is pleased to announce that the 60th Rankine Lecture will be given by Professor Stephan Jefferis of Environmental Geotechnics Limited on The Unusual and the Unexpected in Geotechnical Engineering: Observation – Analogy – Experiment.

This will be held as an in-person event, but booking is mandatory. A booking link can be accessed below. The event will also be webcast live.

Attending the event in person

Proof of registration, either by mobile phone or printed confirmation, will be required to gain entry to the auditorium.

Guests for the Rankine Dinner need not register to attend the lecture, but must bring a copy of their dinner invitation (provided by their dinner host) to gain entry to the auditorium.

The event will be webcast live. A viewing link will be available on the day of the event via this web page.

Covid 19 Precautions mandatory for in-person attendees: for the safety of everyone, please:

  • Take a Lateral Flow Test on the day of the Lecture
  • Wear a mask at all times (NOTE: no refreshments will be served prior to the Lecture)
  • Follow the directions of the stewards through the queueing system, access to the Great Hall will be from 16:45 hrs
  • Provide proof of registration, either by mobile phone or printed confirmation, to gain entry to the auditorium
  • Register in advance online through the link on this page - available shortly
  • Remain in your seat at all times (NOTE: no readmittance if you leave the auditorium)

Watching the live webcast

If you plan to watch the lecture online:

The Lecture will be streamed live via YouTube using this link

No advance registration is required to allow on-line viewing.

The Rankine Lecture

The Rankine Lecture is widely viewed as the most prestigious of the invited lectures in geotechnics. It commemorates William John Macquorn Rankine, Professor of Civil Engineering at Glasgow University, who was one of the first engineers in the UK to make a significant contribution to soil mechanics. He is best known for his theory for the earth pressure on retaining walls.

The Rankine Dinner will be held after the lecture. The Dinner is currently fully subscribed.

This event is free to attend.
Advance booking is required for this event
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Synopsis

The 60th Rankine lecture will explore a wide range of processes which have substantial consequences in geotechnical engineering and yet have received little formal attention.

The lecture will first examine the behaviour of support fluids used in piling, diaphragm walling, tunnelling and horizontal directional drilling – processes which have been strongly influenced by analogies with oil well drilling operations. However, the role of the support fluid in each of these applications is different and it would be a mistake to assume that the key properties are the same for all of them. For example, for decades it was assumed that an excavation support fluid must form a filter cake and should be markedly denser than the surrounding groundwater. The advent of polymer support fluids, which may have little tendency to form a filter cake and have near water densities, has shown these assumptions to be simplistic.

From support fluids, the next step is to consider slurry trench cut-off walls and then the impact of geotechnical activities on soils more generally. On careful analysis, it is apparent that many of the natural processes that occur in soils are mediated by micro-organisms. This adds new dimensions of complexity as there can be multiple outcomes. Construction processes that influence microbiological activity include heating/cooling, tunnelling, dewatering, flooding, sealing with liners, grouting and other introduction of chemicals. These are processes that we regularly undertake without a second thought for their potential microbiological consequences. Fortunately, these usually pass unnoticed and innocuously but occasionally, as will be shown, the effects are at the least unexpected!

Speaker Biography

Stephan Jefferis is a director of Environmental Geotechnics Ltd, a company he established in 1982 anticipating developments in this area. He is a Visiting Professor in the Department of Engineering Science at the University of Oxford. He is a former Chairman of the BGA and was a founder director of WJ Groundwater.

Stephan has worked on major projects across the World including dams, tunnels, shafts and deep foundations. He has over 45 years experience in the investigation and resolution of unusual and unexpected geotechnical problems, often associated with natural chemical and microbiological processes. He has worked on geotechnical processes including fluid supported excavation for decades and is co-author of the book Polymer Support Fluids in Civil Engineering.

An event flyer can be downloaded here

View Flyer


Refreshment Details

No refreshments are available before the lecture.

Lecture theatre doors open at 16:45

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