ABSTRACT
This paper examines the characteristics of highly expansive black cotton soils of India and presents some experiences with foundation design and construction. Foundation failures in these soils are attributed mainly to the differential movement of the structure as a result of uneven ground movements due to alternate swelling and shrinkage of the soil. The use of under-reamed piles in black cotton areas has resulted in economy of as high as 30-60% when compared to strip footings. It is also quick and needs no exta backfilling thus providing for better and more uniform conditions for floor finishes adjacent to the walls.
