Geotechnical study in Lemoa

In Lemoa, limestone, dolomite and marble substrates predominate, accompanied in significant proportions by sandstones, conglomerates and flysch, as well as by deposits of fine sands and silts. These materials generally exhibit low to very low permeability, although they may contain small, shallow aquifers in certain areas. Bearing capacity is usually high in carbonate soils and coarse detrital materials, which normally allows shallow foundations for conventional structures; however, the local presence of fine sands and silts makes it necessary to carry out a careful assessment to rule out problems of heterogeneity or differential settlement.

The municipality’s seismicity is notable, with 94 recorded events over 30 years, although the maximum documented magnitude (Mmax 3.7) does not imply additional structural requirements of any great relevance for ordinary buildings. There are no signs of significant karstification in the area, nor is there any detected risk of expansivity, since the substrate is not clayey. As the main factor affecting conditions in Lemoa, it is recommended that attention be paid to the local heterogeneity of the fine deposits and to water infiltration in specific areas, always ensuring adequate geotechnical investigation prior to any foundation design.