Foundations in Black Cotton Soils:
The following methods are generally adopted to meet the characteristics of foundations in black cotton soils,
(1) Foundation loads are limited to 5 tonnes/sq.m if water finds access to the foundations, otherwise it may be about 10 tonnes/sq.m
(2) Foundations are taken down to such depths to which the cracks do not extend.
(3) Trenches are dug on either side of the foundation and ﬁlled with sand or other material to prevent intimate contact of the black cotton soil with the concrete and masonry of the foundations.
If the thickness of the black cotton soil is only up to 120 cm it should be completely removed and foundation laid on the soil below.
(4) For important buildings raft or mat foundations of reinforced concrete are provided.