Soil mechanics scientists from across the globe gathered in Cambridge for the retirement of Professor Andrew Schofield. Malcolm Bolton reports.
PROFESSOR ANDREW Schofield's retirement as head of the Cambridge University Soil Mechanics Group was marked by an open day at the Cambridge Centrifuge Centre on 12 September, and its renaming as the Schofield Centrifuge Centre.
Past students, friends and colleagues from around the world attended the open day and retirement dinner, where many paid tribute to his enthusiasm and inspiration as he worked to develop clear soil mechanics principles based on meaningful model tests, providing validation of new geotechnical designs.
After launching the UK's first purpose built geotechnical centrifuge at UMIST in 1969, Schofield returned to Cambridge in 1974 to throw his energy into developing the Geotechnical Centrifuge Centre and promoting centrifuge testing internationally. The huge growth in the number and sophistication of geotechnical centrifuge facilities in the last 25 years owes much to his efforts, channelled through the ISSMGE Technical Committee TC2 on Centrifuge Testing, and the successful series of centrifuge conferences which it has sponsored.
Development of the Cambridge school of soil plasticity, and the Cam Clay model of soil behaviour, owed much to the publication in 1968 of the book Critical state soil mechanics, written by Andrew Schofield and Peter Wroth. Various disciples of Roscoe, Schofield and Wroth followed this up with books and papers of their own, and Shibata, Ohta, Sekiguchi and others in Japan independently followed parallel lines of thinking.
Over the succeeding 30 years this has lead to widespread recognition among geotechnical teachers and research workers that the shearing and consolidation of soils was comprehensible within a simple general framework of ideas.
There remains, however, the problem of out of date think- ing endlessly being re- cycled in new text- books, codes and standards (see 'Mohr Coulomb error correction', GE August 1998). A more positive challenge is accommodating to as-yet unresolved phenomena such as cyclic loading, liquefaction, fracture, and time effects, and of developing new engineering systems which will depend for their designs on the acquisition of this knowledge.
Last month, Schofield gave a special lecture to open Centrifuge '98 in Tokyo. Characteristically,
he used the occasion partly to show off the new in-flight technologies achievable in drum centrifuges, and partly to highlight the shortcomings of textbook 'c - ' soil thinking which fails to capture the nature of real events observable in the centrifuge laboratory.
Now that aspects of construction processes such as trenching, embankment construction, pile driving, and tunnelling can be simulated in centrifuges, together with environmental conditions such as earthquake shaking, groundwater variation and contaminant migration, the challenge to old design procedures is bound to intensify.
Guests at the retirement celebrations included Professor Hideki Ohta of Tokyo Institute of Technology; Dr Janet Roscoe, widow of Professor Ken Roscoe who founded the Soil Mechanics Group at Cambridge University in the 1950s; Professor Kandiah Arulanandan from University of California at Davis; Rachel Wroth, widow of Professor Peter Wroth; Professor Sir Alec Broers, vice chancellor of Cambridge University and former head of the engineering department; Professor Jacques Heyman, another former head of engineering; and Professor Robert Mair, Professor Schofield's successor.