Physical and model testing plays an important role in geotechnical engineering research. The scale of problems of interest is typically 10s or 100s of metres, so that 'full-scale' tests are rarely undertaken, and tests at reduced scale are considerably more attractive.
However, the behaviour of soil (or rock) shows extreme dependence on 'ambient' stress, which is considerably smaller in a reduced-scale model.
Geotechnical centrifuge modelling provides the possibility of reproducing full-scale stresses in a reduced-scale model by applying a correspondingly increased centrifugal 'gravity' force. This is arguably the only way in which numerical modelling of geotechnical problems can be verified on a routine basis.
The Nottingham Centre for Geomechanics' centrifuge can be used to study a wide range of civil engineering scenarios (eg slope instability), or soil-structure interactions (eg piled embankments). Problems of more fundamental soil mechanics interest can also be studied (eg the cone penetration test). The reduced-scale models are made from actual soil and miniature structures with appropriate properties. During tests, behaviour of the soil can be observed using digital photogrammetry techniques, whilst structural loads can also be measured. Pore water pressure is readily measured using miniature pressure transducers.