Abstract:

Significant advances in the techniques of bored tunnel construction in soft ground have led to an increasing number of tunnelling projects worldwide, often in urban areas. This lecture highlights the important relationship between tunnelling and geotechnics, and describes recent advances in research and practice, drawing on model studies, theoretical developments and case histories from around the world.

The lecture will discuss simplified models that can be used by designers to assess ground movements and tunnel lining loads in complex ground conditions, illustrated by case histories, together with the important role of pilot tunnels and in-situ measurements to validate such models. Technical advances in tunnel construction processes will be considered, and factors influencing their control to ensure small volume losses will be described. The lecture will discuss recent advances in compensation grouting as a technique for mitigating the effects of potential settlement, illustrated by a recent case history.

The effects of tunnelling-induced settlements on buried structures such as piles, pipes and other tunnels will be considered, with examples drawn from centrifuge model studies and field measurements. Finally, the lecture will present innovative applications of fibre optic technology to field monitoring.

Biography:

Professor Robert Mair was appointed Professor of Geotechnical Engineering at Cambridge University in 1998. He is Head of Civil and Environmental Engineering at Cambridge and was elected Master of Jesus College in 2001. After graduating from Cambridge in 1971 he spent most of his career in industry, including working in Hong Kong for Scott Wilson from 1973 to 1976, at which time he was mainly involved in the design and construction of the container terminals at Kwai Chung; later he was involved in studies relating to MTR projects. He is one of the founding Directors of the Geotechnical Consulting Group (GCG), an international consulting company based in London and Hong Kong, started in 1983. Throughout his career he has specialised principally in underground construction, providing advice on numerous projects worldwide involving soft ground tunnelling, retaining structures, deep excavations and foundations. He has been responsible for geotechnical aspects of many tunnelling projects for the London Underground and is currently involved in the Crossrail project. Recent international projects have included railway tunnels in the cities of bBologna, Florence and Rome, and motorway tunnels in Bolu, Turkey. He is a member of the Review Board for the Singapore Land Transit Authority, advising on all their underground construction projects. He has been a Board Member of the International Society of Soil Mechanics and Geotechnical Engineering, and for the past 10 years has been Chairman of its Technical Committee (TC 28) on Underground Construction in Soft Ground. He was awarded the Gold Medal of the Institution of Civil Engineers in 2004 and is a Fellow of the Royal Academy of Engineering.