The following blog post was prepared in cooperation with Dr. Tim Newson, Associate Professor, Western University, and Cynthia Quintus, GRC Coordinator, Western University.
Due to the complexity of many processes, the analysis and prediction of most engineering phenomena requires a mathematical description or simplified ‘model’ of behaviour that incorporates only the most salient features of process behaviour.
This is precisely what Western University is striving to do through the construction of a 2.2m drum centrifuge facility, which will be fully commissioned by the summer of 2017. Dr. Tim Newson, one of Western’s acclaimed research directors, is currently leading the $5.5M Canada Innovation Fund (CFI) grant proposal. Entitled, ‘Enhancing the Resilience and Sustainability of Critical Geotechnical Infrastructure’, this project will bring together the combined expertise of geotechnical researchers at nine Canadian universities.
The centrifuge facility will provide crucial geotechnical data and predictive models that will enable the development of safe, economical and robust geotechnical structures and processes in Canada. This data can be used to improve our understanding of basic mechanisms of deformation and failure, provide benchmarks useful for verification of numerical models and enable the development and optimization of design and construction methods. The main focus of the work will be the long-term behaviour of geotechnical structures and the development of resilient and sustainable geotechnical solutions able to cope with accumulating damage over time.
The centrifuge is distinguished by its ability to carry a payload around the entire circumference of a large rotating drum. The rotation of the centrifuge permits the scaled physical modeling of geotechnical processes and structures up to 400 times Earth’s gravity, allowing researchers to simulate in-situ or self-weight stresses that exist in a variety of scenarios or problem types.
The centrifuge is particularly suited to modeling long or large single geotechnical structures or processes. Consequently, the initial work will involve the study of components of large public infrastructure, including shallow and deep foundations; pipelines and slope; and underground structures for transportation, utilities and wastewater networks. The centrifuge can also be used to simulate a long site with soil that has a common geotechnical or geological history. Therefore, the centrifuge enables behavioural comparisons for a range of different structures, as well as the replication of tests in the same material.
The addition of novel actuators will also provide a unique modelling environment that can simulate the effects of earthquake loading, cyclic two degrees of freedom loads and displacements, and large fluid waves on geotechnical structures. Essentially, centrifuge modelling permits the simulation of processes that would otherwise be highly time consuming, extremely difficult or even impossible to safely conduct, such as long-term consolidation problems, explosions or contaminated waste studies.
From parametric studies used to identify trigger mechanisms, interpret observations and confirm hypotheses, to the validation of theories and calibration of analytical and numerical techniques, the potential applications of this state-of-the-art facility for geotechnical research are far-reaching.
“Civil and Environmental Engineering: Research.” Western Engineering. 2016. Accessed November 9, http://eng.uwo.ca/civil/faculty/newson_t/research.html.
Western Geotechnical Research Centre. “Scaled Physical Modelling in the Geotechnical Centrifuge.” PowerPoint presentation. Western University, London, ON. http://www.eng.uwo.ca/grc/PPT/Centrifuge.pdf. Accessed November 9, 2016.