Estudio geotécnico in Oiartzun

The municipality of Oiartzun is characterised primarily by the presence of slates and schists, which make up more than 70% of the local geological substrate. These materials, of metamorphic origin, typically exhibit adequate bearing capacity, although their layered arrangement and possible fracturing require a detailed assessment to define the most appropriate foundation. Calcareous formations—limestones, dolomites and marbles—and granite and gneiss intrusions are less frequent, while areas of sandstones and flysch are marginal. In general, the low permeability of most soils limits infiltration, which may affect water-related behaviour beneath the building.

Regarding seismic risk, Oiartzun shows moderate seismicity, with 12 recorded events over the last 30 years and a maximum magnitude of 3, which does not require special structural considerations in geotechnical design. The absence of karstification and the non-clayey nature of the substrate rule out concerns about collapsibility or expansiveness. The main geotechnical constraint in the area lies in the orientation and internal fracturing of the slates and schists, which must be properly studied in order to define safe and durable foundation solutions.