shrinkage

The decrease in volume of soil (or another material) due to contraction, settling, and compaction.

Also, a measure of the decrease in volume of earth material as it is excavated and extracted from its insitu state and then placed into compacted earth fill. This measure is used to compute the compacted in place volume of material meeting the applicable density specification, which can be satisfied through excavation of a specific volume of insitu earth material.

The expected amount of shrinkage for a given soil can be expressed as a percentage of the insitu soil volume (that of the material in its natural state prior to excavation). For example, a shrinkage factor of 9% indicates that the soil will shrink to occupy a volume 9% smaller than it occupied prior to its excavation. This value can also be expressed as a multiplication factor. For example, a soil exhibiting a shrinkage of 9% will have a multiplication factor of 0.91.

See also haul bulkage and haul compaction.