Geotechnical study in Cistérniga

In Cistérniga, subsoils are predominantly formed by compacted gravels and sands, which provides excellent bearing capacity and stability for shallow foundations, thereby favouring the use of surface foundations. However, the occasional presence of gypsum, anhydrite and salts introduces the risk of soil dissolution, a phenomenon that must be considered particularly in areas where these materials crop out, as they may affect ground behaviour in the medium and long term. In addition, the high permeability of the aquifers requires that suitable drainage systems be provided for during construction.

Seismic activity in the area is high, with more than 150 events in 30 years and a maximum magnitude exceeding 4.5, so earthquake-resistant regulations must be integrated from the outset in structural design. The potentially karstic nature, derived from formations with gypsum and limestones, makes a specific verification necessary before defining the foundation solution, in order to avoid problems associated with underground cavities. Given the absence of expansive clays, the risk of expansivity is ruled out, focusing the technical attention on seismicity and the dissolution processes associated with soluble substrata as key conditioning factors for any geotechnical study in the municipality.