|
Black clay soils or tropical black earth or black cotton
soils are known to be potentially expansive soils. They
classify in pedological parlance as Vertisols and have been
subject of considerable agricultural and engineering
research especially in India and some African countries. The
black cotton soils are considered “problematic” and
sometimes as “potential natural hazard” because they cause
extensive damage to light structures founded on them due to
excessive seasonal volumetric changes (swell and shrinkage).
Considering the widespread prevalence of black cotton soils
around the world and the geomechanical challenges they pose
to structures founded on them, we need to understand the
peculiar characteristics and behaviours to enable effective
utilization of these soils for engineering purposes. As a
first step there is a need to assemble, correlate and
integrate useful information on the genesis, nature and
distribution as well as some basic geotechnical
characteristics of the black cotton soils useful for civil
engineering purposes scattered in various journal papers,
proceedings of conferences, symposia, workshops, etc.
Secondly, there is also the need to add value to existing
knowledge in terms of technical information relating to
geology and geomechanics of the black cotton soils occurring
in Ghana through laboratory and field studies. The paper
attempts to review the literature on the state of the art.
The review relates to the raw soils and has not discussed
improvement and stabilisation aspects.
Keywords:
Weathering, classification,
problematic, potentially expansive, black cotton soil
|
