Estudio geotécnico in Santa Ana Valley

In Valle de Santa Ana, the predominant subsoil comprises sandstones, conglomerates and flysch, representing more than 88% of the ground, followed by igneous formations such as granite and gneiss that occur occasionally. These lithologies generally exhibit good bearing capacities and low deformability, which is favourable for supporting shallow foundations, provided that the thicknesses of alteration are rigorously assessed. However, the presence of flysch may require more detailed analyses to characterise possible intercalations of lower competency. Permeability is low, although small near-surface aquifers may sometimes occur associated with discontinuities, which is an aspect to be considered in the excavation and drainage phase.

Seismic activity in Valle de Santa Ana is notable, with 52 recorded events over 30 years and a maximum magnitude of 4.4; although the magnitude does not exceed a relevant threshold, the recurrence of seismicity is a factor to be considered in structural design. There is evidence of karstification in the region, which makes it necessary to carry out a specific assessment of the existence of cavities before defining the foundation, in order to minimise the risks of differential settlements or localised collapses. The subsoil does not have an clayey nature, so the risk of expansivity is ruled out. As the main constraint for geotechnical interventions in the municipality, the need to verify karst processes stands out and ensuring that the structural design accounts for the level of seismicity.