Geotechnical study in Moaña

In Moaña, the predominant materials of the subsoil are sandstones, conglomerates and flysch, together with slates and schists in significant proportions. These lithological formations, of coherent nature and moderate to high strength, generally provide good conditions for direct foundation. The residual content of fine sands and silts is scarce, thereby minimising the risk of compressible soils, and the presence of water bodies is only occasional, so constructive interventions typically benefit from favourable bearing capacity, although it is recommended to assess the specific location of surface aquifers associated with low-permeability layers.

From the seismic standpoint, Moaña shows moderate seismicity, with 47 events over 30 years, but with low maximum magnitude (Mmax 2.9), so its impact on structural design is limited. No significant karstification phenomena occur in the area and, since the predominant bedrock is not clayey, the risk of expansiveness can be ruled out. Therefore, the main geotechnical considerations for Moaña focus on appropriate characterisation of the stratigraphy and assessment of local subsoil impermeability.