Geotechnical study in Valverde de Mérida

In Valverde de Mérida, igneous rocks predominate as the substrate, such as granites and gneisses, accompanied in places by deposits of gravels, compact sands and, in smaller proportions, fine sands, silts and hard overconsolidated clays. The frequent presence of rock formations gives the ground a high bearing capacity, facilitating shallow direct foundations in many cases, although the local depth and characteristics of the granitic layers must be assessed. Water masses are relatively common, which may imply high groundwater levels in certain areas and therefore should be taken into account in the design of strip footings and buried elements.

Seismic hazard in the municipality is notable: 52 events have been recorded over 30 years with a maximum magnitude of 4.4, so seismic risk should be assessed in the structural design concept. The predominantly non-clayey substrate rules out a significant risk of expansivity for the foundations. Overall, the arrangement of hard rocks, together with the observed seismicity, indicates that the main determining factor is the appropriate adaptation of the foundation to the rocky substrate and the incorporation of seismically resistant design criteria in the structural design.