Abstract:
Partially saturated soils are often dense with a high bearing capacity and will subsequently only suffer
small amounts of compression under normal foundation loads. However, when wetted under load many
such soils undergo a marked and sudden increase in settlement, the phenomenon that is known as collapse
settlement.
It was originally assumed that the collapse phenomenon is largely restricted to loose aeolian deposits,
with the result that most of the research and work dealt almost exclusively with such deposits. However,
the collapse phenomenon has since been identified in a number of different transported soils as well as
residual soils, most notably the residual granitic soils associated with the Basement Complex of South
Africa.
Recent studies suggest that the geological origin of the material plays an important role in the collapse
mechanism of the particular material. This paper highlights the differences between the collapse process
in transported and residual soils by focusing on the geological origin of the material.