Granular media behaviour determn. - by establishing stress-strain curves of new shapes from known curves

摘要

A method of determining the behaviour of granular media, e.g. geological materials such as the components of embankments, barrages and foundations, for safety purposes by establishing the stress/strain relationship of type sigma = f(epsilon), involves determining this relationship for any new shape using the known relationship for any simple shape. Pref. the method involves determining the relationship for a material, knowing the relationship for the same shape of another material. The shape of the material is pref. characterised by Cf-dmax (ratio between the vol. of a grain of the material and the vol. of a circumscribed sphere) and Cf-t (ratio between the volumes of inscribed and circumscribed circles of the grain). The method may also involve choosing a 'secondary grain rupture' coefficient defined as the rupture stress of a cube of equivalent size to that of a grain of the sample to be studied. When the material comprises grains of different shapes, the method pref. involves classifying the grains according to shape, establishing a curve f(epsilon) for each shape and obtaining an approximation of the characteristic curve of the material by a mathematical averaging method. The method may involve separately preparing a curve epsilon = f(Cf-dmax) for low stresses and a curve epsilon = f(Cf-t) for high stresses, followed by combining the curves to obtain the curve sigma = f(epsilon).