Geotechnical study in Santa Eulària des Riu

In Santa Eulària des Riu, compact gravels and sands predominate, together with a significant presence of limestones, dolomites and marbles. This composition provides a substrate with good bearing capacity and favourable conditions for direct foundations in most projects. However, the occasional presence of overconsolidated clays and marls, although in a smaller proportion, suggests the need for accurate characterisation to optimise the selection of the foundation type and to avoid surprises during execution stages. The permeable properties of the ground allow for adequate drainage of water, but the heterogeneity of the aquifers requires a detailed assessment at plot level.

Seismic activity in the municipality is of moderate intensity, with 24 events recorded over 30 years and a maximum magnitude of 3.2; therefore, seismic risk is low and does not significantly condition structural design. It is important to highlight the notable presence of carbonate materials, which implies the possibility of karst processes; consequently, it is essential to thoroughly verify the existence of cavities before any foundation is constructed in order to avoid differential settlements. The non-clayey substrate rules out the risk of expansivity, with karst control being the main technical factor conditioning the viability of the foundations.