Geotechnical study in Sástago

In Sástago, the subsoil is dominated by the significant presence of gypsum, anhydrite and salts, with occasional accompanying limestones, dolomites, marbles and sandstone formations. These lithologies condition both the ground’s bearing capacity and the available foundation options, since gypsum and anhydrite present a risk of dissolution, which can lead to differential settlement if they are used as a bearing level. In addition, the high permeability of the local aquifers demands special attention when designing foundations, in order to avoid problems associated with the migration or leaching of soluble materials.

Seismicity in the area is moderate, with 45 recorded events over the last 30 years and a maximum magnitude of 2.7, which implies a limited influence on structural design. Nevertheless, due to the karstifiable nature of the subsoil, it is essential to carry out specific checks to rule out the presence of cavities or instabilities before defining the most suitable foundation solution. The absence of an clayey substrate eliminates the risk of expansivity, focusing technical attention on the issues associated with karst and the solubility of the materials present.