Geotechnical study in Gijón

In Gijón, the predominant subsoil is made up of sandstones and conglomerates, materials that exhibit good mechanical properties and provide adequate bearing capacity for building. Although less common, flysch and the occasional presence of limestones, dolomites, and marbles can locally alter foundation conditions, whereas fine sands and silts, as well as slates, occur more limitedly. The characteristic low permeability of these formations may favour the existence of shallow aquifers, but generally they do not represent a significant problem for founding conventional structures on these subsoils.

In terms of seismic hazard, Gijón experiences moderate seismicity, with 15 events over 30 years and a low maximum magnitude (Mmax 1.7), so its influence on structural design is limited. The noteworthy feature in the region is the possible occurrence of karst processes due to the presence, although in the minority, of limestones and dolomites; in these cases, it is essential to check for cavities before defining the foundation. With a non-clayey subsoil, the risk of expansivity is ruled out, and verification of karst is the factor that may most significantly condition the feasibility and the type of foundation to choose in this municipality.