On the behaviour of Thanet Sand: An example of an uncemented natural sand

An extensive laboratory investigation was made of the mechanics of Thanet Sand, testing the soils from a number of locations and depths in the triaxial apparatus over a wide range of stress levels. Comparisons between tests on intact and reconstituted samples and between vertically and horizontally trimmed intact samples highlighted the effects of structure on the behaviour of this uncemented sand, in particular a significant effect of anisotropy. Two distinct substrata have previously been identified with different fines contents, and the key difference in their behaviour has been found here to be the location of their Critical State Line in the v.lnp' plane, which has a significant effect on the engineering behaviour of the two substrata and can explain recent unusual observations of decreasing pile capacity with depth. Tests in which the glauconite content was removed from the sand showed that it did not affect its behaviour.