Settlements in sand deposits are classified as immediate and the greater part of these develop as the construction phase proceeds due to the progressive application of loads and vibrations that can be detected by the Pipe Borescope.
In general it is evaluated incorrect practice to lay foundations on sand deposits where the relative density is not ≥ 60% or that do not have a density close to about 90% (or more) than the maximum achievable in the laboratory. This thickened condition reduces the possibility both of failures due to loads and of any settling damages due to vibrations generated by the passage of construction vehicles, earthquakes etc.
The lands prone to collapse are generally wind deposits or deposits of the lossic type, sand dunes and volcanic ash. The loss from the sedimentological point of view, are considered to be loose soils.