The geotechnical or mechanical survey is a type of manual or mechanical prospecting, belonging to the geotechnical recognition techniques of the terrain, carried out to know its characteristics. These are small diameter drillings (between 65 and 140 mm) that, although (generally) do not allow in situ viewing of the ground, from them you can obtain witnesses of the drilled ground, as well as samples, and carry out certain tests inside. Exceptionally, cameras and video equipment can be used for on-site diagnosis of the interior.

Note: It is impossible to carry out these studies on the vegetal layer, in addition to being unnecessary, since it must be restored for the construction of a road or pavement. Other types of drilling are diamiamantine or diamond drilling.

Leaving aside manual drilling with an auger or spoon, mechanical drilling is proposed for the following requirements:

Mechanical probing systems:

The most widely used method in Spain is helical drilling with hollow probe, followed by rotational drilling with continuous core extraction.

After carrying out a borehole, it is advisable to record the temporal variation of the water table, for which a slotted PVC pipe will be left inside the borehole, suitably covered.