The first question is: what does the diameter of the circle in a Mohr Circle of Strain equate to?

Post your answer here:

To celebrate the launch of University College London and itmsoil’s new Performance Monitoring training course, we are giving one lucky reader the chance to win a place on the two-day course, worth GBP 700 (USD 1,087).

Ten runners up will win a copy of the course book – A Guide to Field Instrumentation in Geotechnics written by Dr Richard Bassett – worth GBP 90 (USD 140).

Featuring expert speakers delivering powerful industry relevant knowledge and hands-on sessions, the new course is invaluable to those wanting to gain a sound understanding of the monitoring techniques and instruments available, their uses and limitations and also how to communicate the value of monitoring to stakeholders.

The course takes place on 13 and 14 September 2012 at University College London and itmsoil headquarters in Uckfield, East Sussex. For more information, please visit

The closing date for August questions is Wednesday 29 August 2012.
Correct answers will be entered into the prize draw and winners will be announced in the newsletter the week the competition closes. World Market Intelligence Ltd (the Publisher reserves the right to withdraw the quiz at anytime. The Publisher may withdraw the prize at anytime. No alternative prize is available and the prize is not transferable. There is no cash equivalent. For winners details please send a stamped, self addressed envelope to Tunnels and Tunnelling, John Carpenter House, 7 Carmelite Street, London EC4Y 0BS, UK.