Geotechnical study in Besalú

In Besalú, the dominant substrate consists of compact gravels and sands, which represents approximately 68.75% of the total, providing excellent conditions for bearing capacity and facilitating shallow foundations. Fine sands and silts are also common, which may require additional density and consolidation studies to ensure ground stability. The occasional presence of gypsum, anhydrite and salts introduces a risk to consider due to possible dissolution processes; therefore, their identification and delineation are recommended in the geotechnical study campaign, especially if deep excavations are planned.

The seismicity in Besalú is very low, with only 2 recorded events over 30 years and a maximum magnitude of 1.6, meaning it does not constitute a relevant constraint for structural design. In addition, the substrate is classified as non-clayey, ruling out the presence of risks associated with clay expansivity. As the main constraint for the area for the geotechnical study, the possible appearance of soluble materials stands out; it is therefore a priority to analyse the integrity of the ground in relation to its potential dissolution before defining the foundation solution.