Geotechnical study in Nava

In the municipality of Nava, the main subsoil is composed of slates and schists, occasionally accompanied by fine sands, silts and some formations of sandstone, conglomerates and flysch. Masses of muds and peats of deltaic origin can also be identified, though in a very sporadic way; these should be avoided as a foundation level due to their low bearing capacity and high compressibility. The prevailing low permeability of these soils favours stability but limits drainage, which must be taken into account in the foundation design to ensure adequate support and avoid differential settlement.

With regard to seismicity, Nava shows very low seismic activity with a maximum of low magnitude, which represents a minimal risk for building in this respect. The non-clayey subsoil rules out problems associated with expansiveness, but the presence of possible karstic phenomena linked to the regional geological composition requires prior verification of the risks of settlement or localised collapse before carrying out any foundation work. Therefore, the main geotechnical constraint for the area is the need to assess the possible existence of karst cavities together with the appropriate selection of the bearing level, especially avoiding areas with the presence of muds or peats.