Estudio geotécnico in Portomarín

In Portomarín, slate and schist substrates predominate, representing more than 70% of the materials in the subsoil, followed by the occasional presence of granite, gneiss and other igneous rocks. These soil types are characterised by generally high bearing capacity, although they may show some local variability in terms of fracturing and weathering. The formations have very low permeability, which limits the infiltration of water, although surface aquifers may exist in specific areas. For foundations, surface solutions are usually used in stable areas, with direct founding on the bedrock, thereby ensuring adequate support for buildings.

Seismicity in Portomarín is very low, with only around three recorded events over thirty years and a maximum magnitude of less than 4,5, so seismic risk does not represent a relevant consideration in geotechnical design. The non-clayey substrate eliminates the risk of expansivity, allowing problems associated with significant swelling to be ruled out. Therefore, the main geotechnical constraint in the municipality lies in adequately characterising the fracturing of the bedrock materials and verifying the presence of any potential zones of local weakness.