Geotechnical study in Catoira

In the municipality of Catoira, the predominant subsoil is mainly composed of sandstone, conglomerates and flysch, accounting for more than 80% of the ground. These materials are known for their compactness and generally favourable behaviour under loads, which provides good bearing capacity for the foundation of new buildings. On the other hand, areas with fine sands and silts, although less frequent, may require additional targeted studies to assess the possible compressibility and ensure foundation stability, avoiding undesirable differential settlements.

Seismic activity in Catoira is classified as moderate, with 47 events of small magnitude recorded over 30 years and a maximum magnitude of 2.9, which implies no special considerations for structural design in seismic matters. There are no relevant karst processes in the area, and the absence of expansive clays in the subsoil eliminates the risk of expansivity, ensuring stable conditions for founding. Thus, the main constraint for the geotechnical study lies in the localised variability of less consistent materials, rather than in risks associated with seismicity or expansivity.