Geology Reference
In-Depth Information
Exercise 17 • Geology and Regional Planning
265
FIGURE 17.5
Capability of soils for residential foundations based on shrink-swell potential. The
most capable
soils have a
low shrink-
swell,
here defined as less than 0.5 inch rise (in 6 feet of soil or to bedrock) when a fully dry soil is thoroughly wetted. The
least ca
pa-
bje soils have a
very high shrink-swell
hazard with a rise of more than 2 inches. Soil thickness, clay type and amount of clay influence
shrink-swell. Climate, on-site mangement of water, drainage and vegetation also influence the hazard.
(Modified from Elder, 1965; used with permission.)
