Geotechnical study in Merindad of Río Ubierna

In the Merindad de Río Ubierna, the dominant subsoil is made up largely of limestones, dolomites and marbles, which provides a competent ground with high bearing capacity and suitable conditions for shallow foundations in most cases. In smaller proportions, sandstones, conglomerates and flysch also occur, as well as small areas with gypsum, anhydrite and salts; and some locally limited zones with gravel, compacted sands or silts. The presence of extensive aquifers, generally highly permeable, may influence water behaviour, but overall these materials usually facilitate conventional foundation solutions.

Seismic activity in the area is very low, with only 3 recorded events over 30 years and a maximum magnitude of 1.9, so seismicity does not particularly affect structural design. However, the risk of karstification associated with the limestone and dolomitic levels requires specific verification prior to any foundation, as cavities or unstable zones may be present. The subsoil is not clayey, which eliminates the risk of expansive behaviour. Therefore, the main geotechnical constraint for projects in this municipality is possible karstification, which must be assessed carefully by means of a detailed geotechnical study before construction works are carried out.