Geotechnical study in Girona

In the municipality of Girona, geotechnical studies find that the dominant subsoils are slates and schists, followed by compact gravels and sands, as well as the occasional presence of limestones, dolomites and marbles. This predominance of hard materials with low permeability generally facilitates a good bearing capacity for the foundations of structures, although in specific areas groundwater can be found at depth. The occasional presence of granitic soils, gneisses and sandstones provides additional stability, while in sectors dominated by compact gravels and sands favourable conditions can be observed for shallow foundations.

As regards seismicity, Girona is characterised by very low seismic activity (2 events over 30 years and a maximum magnitude of 1.6), so seismic risk does not significantly condition structural design. However, the occasional occurrence of carbonate materials such as limestones and dolomites implies the possibility of karstification phenomena developing, so it is essential to verify the existence of cavities before proceeding with any foundation. The non-clayey substrate eliminates concerns related to expansive soils, with control of karst being the main geotechnical constraint in the area.