Geotechnical studies and investigations are a complement to geology and hydrogeology.
Their objectives are to know the basic characteristics of the ground which will have an impact on the mechanical behavior of the rock or soil, the initial state of equilibrium of the natural stresses and the changes of loads and actions that will be exerted over the structure during the construction and operation.
In order to do so, geotechnical investigations aim at quantifying the geomechanical characteristics of the ground by means of different parameters that are dependent on both the micro and the macro structure.
For instance, the mechanical behavior of a rock mass will depend not only on the composition and mineralogical structure of the rock matrix itself, but also on the presence and characteristics of the different faults, cracks and joints that will appear on the rock mass, weakening its general strength and changing the way it behaves at the underground structure scale.