Geotechnical study in Villanueva del Río y Minas

In Villanueva del Río y Minas, the dominant geological substrate is made up of slates and schists, which make up almost one third of the soils present and show characteristics of low permeability. Compact gravel and sand provide occasional areas with better bearing capacities, while the marginal presence of fine sands, silts and masses of water indicates the need to analyse possible zones of low consolidation, particularly in proximity to watercourses. To determine bearing capacity and define the appropriate foundation, it is essential to evaluate in detail the distribution of these materials, especially in the face of heterogeneity in competing substrates and the need to avoid bearing on unconsolidated materials.

The seismicity in the municipality is very low, with only 4 catalogued events over 30 years and a low maximum magnitude, which limits its influence on structural design. However, the potential development of karst phenomena, associated with the presence of limestones, dolomites and marbles even if they are rare, requires a thorough geotechnical assessment of the ground before executing any foundation, in order to rule out subsidence or instabilities. Given the non-clayey nature of the substrate, the risk of expansion is insignificant. The main geotechnical condition to consider is therefore the possible existence of isolated karst cavities or instabilities.