Prof. Chris Clayton
BSc MSc DIC PhD CEng FICE CGeol FGS
Emeritus Professor of Infrastructure Engineering
Prof. Chris Clayton is an Emeritus Professor of Infrastructure Engineering at the University of Southampton.
After graduation, Professor Clayton's early career was spent in industry, working as a specialist geotechnical engineer in site investigation and civil engineering contracting. In 1972 he took a year out to study for his Master’s degree at Imperial College, which he completed with distinction. On his return to industry he combined commercial and academic research, and was awarded a collaborative PhD by the University of Surrey in 1978. On completion of his PhD he joined the University of Surrey as a Lecturer in Geotechnical Engineering, becoming Professor of Geotechnical Engineering in 1992. He joined the University of Southampton in 1999.
Prestigious lectures
- British Geotechnical Association Géotechnique Lecture - 1999
- Institution of Civil Engineers Unwin Memorial Lecture - 2001
- South African Institution of Civil Engineering Jennings Memorial Lecture - 2006
- British Geotechnical Association 50th Rankine Lecture - 2010
- 2nd Korean Geotechnical Society Lecture - 2012
Books, national reports, and guidance documents
- Graduate textbooks on ‘Site Investigation’ and ‘Earth pressure and Earth-retaining Structures’
- CIRIA reports on procurement of ground investigation, engineering in chalk, and on the SPT
- ICE / DTR report on ‘Managing Geotechnical Risk’
- Member of HSE board for the 1994 Heathrow Tunnel Collapse investigation.
Editorships
– Proc. ICE Geotechnical Engineering – 1993-1996
– Q. J. Engineering Geology and Hydrogeology – 1997-2000
– Géotechnique 2009-2011
– South African Inst. Civil Engineering J. (2000- present)
Research
Contact
Research interests
Chris Clayton’s research, focusing on geotechnical site and material characterisation, has been largely application driven, and has been backed up by research and development using field monitoring (for example of tunnels and retaining structures), advanced laboratory testing and instrumentation, and by investigations into the stiffness and strength behaviour of unusual geomaterials, such as the chalk.
Examples of recent and current research themes are:
Mechanical properties of hydrate-bearing sediment
Internal fluidisation of granular soils
Stiffness of unsaturated soil
Effects of particle shape on dilation
Cyclic strength of destructured chalk
Fig. 1
Effects of dissociation of methane hydrates on the mechanical properties of sea-floor sediment.
Methane hydrate dissociation has been associated with tsunami-triggered sea-floor slope instability. This research is also relevant for the design of hydrate “mining” methods, and to the interpretation of the seismic geophysics used to detect the presence of hydrates. Our research has shown major differences in stiffness (and therefore strength) of hydrates formed in different sediments. See Fig. 1.
Fig. 2
Mechanisms of Internal fluidisation of granular materials.
The mechanism of internal fluidisation exposed by this work has not previously been recognised in civil engineering. It has widespread application, for example in understanding leakage from water distribution pipes, through dams and sheet-pile retaining structures, maintenance of channels in ports, understanding the distribution of diamonds in pipes, and in chemical and process engineering. See Fig. 2.
Fig. 3
Stiffness of unsaturated soil.
Climate change won’t just change sea levels. We can expect that changes in rainfall magnitude and pattern will affect the strength and stiffness of the unsaturated ground that is near-surface. Advanced laboratory tests have shown that suctions can produce large changes in stiffness and permanent deformation under cyclic loading. This is important for all shallow infrastructure, and particularly for the design and performance of rail formations. See Fig. 3.
Fig. 4
Effects of particle shape on dilation.
Dilation, first demonstrated by Osborne Reynolds in 1885, makes a major contribution to the strength of dense granular materials. Reynolds believed that dilatancy occurred in all dense, regardless of particle shape, but our research has shown that while it exists in rotund materials it is suppressed in materials composed of platy particles. This finding is of particular importance in understanding and preventing the failure of gold tailings dams. See Fig. 4.
Fig. 5
The cyclic strength of de-structured chalk
The chalk underlies about 15% of the UK and a significant amount of the North Sea and Northern Europe. Undisturbed, it is a weak rock, but when crushed (for example during piling or highways earthworks, soft chalk can become a putty. Strength and stiffness changes as a result of de-structuring, consolidation and cyclic loading are being measured. These data are important when designing structures such as mono-piles foundations for offshore wind turbines. See Fig. 5.
Large-scale landslides can seriously threaten human life and infrastructure over extensive areas, by rapidly moving substantial volumes of material and even by causing catastrophic tsunamis. Better understanding their mechanics is key for predicting such events and protecting ourselves from their consequences.
It is estimated that effective management of irrigated agriculture in the Aral basin could save up to 10% of the region’s water, doubling the flow to the severely degraded lower reaches and contributing significantly to the preservation of the region’s biodiversity and its human and natural ecosystems. This research aimed to provide a scientifically-proven methodology by which agricultural land use can be determined from multi-spectral satellite imagery. The method was then applied, in conjunction with an existing water resource management model for the Syr Darya river, to provide up-to-date information for calculation of crop water demand. The result is a cost-effective system that is capable of identifying the extent and location of wasted irrigation water, and of examining the effects of alternative management options. The overall goal was to provide practical tools that will allow rational planning and utilisation of the Aral basin's land and water resources.
A testing programme of short and long-term compression, tension and direct shear tests has been carried out on samples cut from SCL panels built up with a primary layer, sprayed waterproofing membrane and sprayed secondary layer. These tests have demonstrated the mechanical properties of the concrete-membrane-concrete interface for different surface roughness and membrane thickness. The degree of composite action available between the primary and secondary linings through the membrane interface has been validated through further laboratory tests on beam samples, the results of which have been used to calibrate a numerical model of the composite shell lining. This modelling approach has in turn been applied to typical full-scale tunnel geometry to examine the influence of the composite action between the lining layers on the behaviour of the tunnel as a whole. Parametric studies have been carried out with variation of interface parameters and secondary lining thickness, and preliminary results show it should be possible to achieve savings in overall lining thickness.The research is supported by Mott MacDonald, international consulting engineers, and by Normet (UK), construction (mining and tunnelling) products manufacturer.
Prof. Chris Clayton
Engineering, University of Southampton, Southampton Boldrewood Innovation Campus, Burgess Road, Southampton, SO16 7QF
