Choice of models for geotechnical predictions

The stress path approach in identifying critical soil elements in association with a variety of geotechnical structures is discussed. The following situations were discussed: the stress path on a soil element on the centerline beneath a circular load; the stress path for an element behind a retaining wall; for elements adjacent to an excavation; for elements beneath a long embankment; and for elements adjacent to a pile or pressure meter. The essential features of Cam clay models, exemplifying a series of simple elastic models, were described. However, since this model is not always successful in matching this observed experimental path, it was suggested that caution should be exercised in making geotechnical predictions which involve extrapolation into a region outside the premises of the model.