Geotechnical study in Santa Eulalia

In Santa Eulalia, the predominant geological substrate is composed of sandstones, conglomerates and flysch, with a significant presence of limestones, dolomites and marbles, and a smaller fraction of gypsum, anhydrite and salts. This combination of materials indicates that, generally, the soils have a favourable bearing capacity for direct foundations, particularly on the more compact formations. However, the occasional presence of gypsum and salts points to a potential risk of dissolution, which can give rise to subsidence if these horizons are not adequately assessed. The overall low permeability of the strata requires attention to drainage, although relevant aquifers may occur at depth.

The seismicity in the municipality is moderate, with 10 events in the last 30 years and a maximum magnitude of 3.4, which does not represent a significant threat for structural design. It is important to highlight that there is an environment conducive to the development of karst phenomena due to the presence of limestones, dolomites and marbles; therefore, any potential karst must be verified before defining the type of foundation. The absence of clayey substrates rules out problems of expansivity, leaving as the main technical constraint the assessment of cavities and dissolutions in the ground.