Estudio geotécnico in Fregenal de la Sierra

In Fregenal de la Sierra, shales and schists predominate by a wide margin, representing more than 70% of the soils, followed by the occasional presence of granite, gneiss and other igneous rocks. These lithologies are characterised by being hard materials, with low to very low permeability, which favours adequate bearing capacity for building and allows direct foundations in most cases. It is important to consider the possible presence of superficial aquifers in specific areas, although they usually do not compromise the overall stability of the ground to be founded upon.

Seismicity in this municipality is very low, with only one recorded event in 30 years and a low maximum magnitude; therefore, seismic risk is practically negligible. However, owing to the presence of ground that may be karstified in the area, it is essential to verify the existence of cavities and karst processes before carrying out the foundation works, as these could affect the stability of the structures. There are no risks associated with expansivity, since the dominant substrate is not clayey. The main geotechnical factor is therefore the investigation and monitoring of karst, which must be addressed in any geotechnical study prior to the project.