Abstract
Many engineering projects are designed on the basis of laboratory tests using so-called ‘undisturbed’ samples of clay taken from the field. There is a tendency to test only intact specimens and discard specimens that appear disturbed, fissured or otherwise weaker. It is known, however, that natural processes such as wetting-drying, freezing-thawing, desiccation, heating-cooling, and alterations in chemistry can affect the structure of clays and significantly change their compressibilities, hydraulic conductivities and strengths. For example, plastic clays that have been fissured by desiccation or freezing cannot reliably provide peak strength resistance in slopes and under engineered embankments. The paper shows examples of projects where natural processes degraded the strengths of natural and reconstituted clays. The case histories in the paper provide a reminder of the importance of recognizing natural processes and the limitations of laboratory measurements when selecting appropriate parameters for numerical modeling.
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Graham, J., Alfaro, M., Blatz, J. (2011). Natural Processes and Strength Degradation. In: Wan, R., Alsaleh, M., Labuz, J. (eds) Bifurcations, Instabilities and Degradations in Geomaterials. Springer Series in Geomechanics and Geoengineering, vol 0. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-18284-6_11
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DOI: https://doi.org/10.1007/978-3-642-18284-6_11
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