Geotechnical analysis of soil

Geotechnical analysis of soil is carried out through techniques that are specific to the type of soil to be analyzed and through which different levels of detail can be achieved. The easier and less expensive types of on-site tests are the dynamic penetration tests that are particularly suitable for soils with predominant sand make up and that can provide diagrams from which it is possible to obtain the stratigraphic lay-out of the soil, the relative density, the friction angle and the parameters of deformability. The limitation of these tests is the presence of pebbles and boulders in the ground (frequently in the case of glacial deposits), which can prevent the effective penetration of the probe; these tests are in any case limited to the more superficial layers.

A greater depth of survey can be reached with the execution of geotechnical drilling. Depending on the depth to be reached and the type of material to be passed through, they can also be performed with small sized machinery, thus lowering costs. The drillings also allow site tests in the borehole to be performed and to take samples to be used for laboratory tests. The drilling holes can also be equipped with piezometric pipes that make periodic readings possible or to install electrical piezometers which enable the continuous monitoring of the aquifer.

The laboratory tests, whose type and entities are very variable depending on the type of soil and on the purposes of the analysis, vary from the geotechnical description to identification and classification tests, to consolidation tests, to shear tests, to permeability tests, for the measurement of the deformability parameters.