Estudio geotécnico in Lillo

In the municipality of Lillo, sandstones, conglomerates and flysch predominate, frequently accompanied by gypsum, anhydrite and salts, and in smaller proportions, limestones, dolomites, marbles and slates. This geological formation offers generally favourable bearing capacity, although the presence of gypsum and salts entails an added risk of dissolution under certain conditions, which may compromise the stability of foundations if a detailed investigation is not carried out. Expansive clays are practically non-existent in the area and, therefore, the risk of expansivity associated with the subsoil is negligible. It is essential to select the competent stratum and avoid differential settlement due to lithological heterogeneities.

In terms of seismic hazard, Lillo has only 3 significant events in 30 years and a maximum magnitude of 2.7, indicating very low seismicity, with no special requirements in this aspect for structural design. However, the possible presence of karstic cavities due to the nature of the gypsum and carbonated materials makes an exhaustive assessment necessary through boreholes and tests before defining the appropriate foundation solution. The determining factor in the geotechnics of the municipality is, without doubt, the prior verification of karstic phenomena and dissolution processes associated with gypsum and salts.