Edinburgh Napier University

  Geotechnical centrifuge modelling provides an opportunity to examine novel and complex events in a well-controlled and repeatable environment. While grain interaction and contact dynamics are considered in centrifuge modelling, the soil is treated as a continuum, consistent with standard geotechnical analysis. In the last four decades, particle size effects have been normally approached by the ratio of median particle diameter to critical dimension of modelled structure. The current study considers the response of a granular medium in a centrifuge model by coupling physical tests and equivalent discrete element simulations. The response of a strip footing on uniformly graded glass ballotini is investigated. This is chosen as the sample characteristics can be accurately replicated in a discrete element simulation. Particle size distribution, gravity and footing width are scaled in the context of model-the-model technique and the sensitivity of the bulk response to rapid increase in stress level is explored. This will help establishing the link between the micro phenomena and the macro response and contribute towards improving geotechnical design. The paper describes the work conducted to overcome challenges related to physical modelling including particle mixing, sample preparation, image analysis, and loading apparatus.