ABSTRACT
There is a group of geohazards that exist largely because of the geotechnical properties of the material concerned, which in turn are commonly related to its fabric and mineralogy. This group of geohazards includes, for example, swelling and shrinkage of some clay soils, dispersivity in clay soils with particular chemical characteristics, and the collapse potential of certain silty soils. Other soils such as quicksands, quick clays and peat lack strength, the first two especially when disturbed, which can give rise to major problems. The effects of these hazards, while unspectacular and rarely causing loss of life, can result in considerable financial loss. Swell—shrink in clay soils, for example, has caused losses of up to £2 billion in recent years in the United Kingdom. The use of dispersive soils in southern Africa, Australia and the United States has led to the failure of dams and road embankments.
