What Does Granular Disturbed Sample Mean?
Granular disturbed samples refer to soil samples derived from the sub-surface using a split barrel sampler used for a standard penetration test (SPT). Granular soils include sand and medium-sized gravel and silt that have water draining properties and are in the state of maximum density when fully dry or fully saturated.
It has no cohesive strength and cannot be molded even when water is added and crumbles easily when dry.
Trenchlesspedia Explains Granular Disturbed Sample
A standard penetration test (SPT) is carried out in soils where it is not possible to bring out an undisturbed sample such as in granular soils due to its lack of cohesion. The high permeability of granular soils allows them to drain quickly when loaded.
The SPT test provides an indication of the relative density of the granular deposit and its approximate shear strength.
Moist granular soil with small amounts of cohesive material can be remolded to simulate in-situ conditions for shear strength testing. The SPT results can be used to determine the relative density, settlement and bearing capacity of granular soils.