Geotechnical study in Gandia

In Gandia, the predominant composition of the subsoil is dominated by limestones, dolomites and marbles, accompanied by frequent fine sands and silts. The presence of these materials generally implies favourable bearing capacity in most of the municipality, thanks to the mechanical strength of the carbonated materials and the compactness of some sandy fractions. However, the possible occurrence of white or soft expansive clays, although occasional, requires special attention in the identified areas, as they can affect the uniformity of the settlement of shallow foundations. The high permeability levels associated with the presence of extensive aquifers must also be taken into account for foundation design and protection against moisture.

Seismicity in Gandia is classified as very low, with only 5 events over 30 years and a maximum magnitude below 4.5, so it does not represent a relevant constraint for conventional structural design. However, as it is a geological setting dominated by carbonated materials, it is essential to carry out a prior verification of karst phenomena before proceeding with the foundation, due to the potential presence of underground cavities and sinkholes that could compromise stability. Finally, the absence of a predominant clayey substrate makes it possible to rule out the risk of expansivity as a determining factor.