Geotechnical study in Gallur

In Gallur, the ground is composed mainly of fine sands, silts, sandstones and conglomerates—materials that exhibit good bearing capacity due to their compactness and stability. The significant presence of gravel and compact sands supports the viability of shallow foundations, provided they do not interfere with occasional water levels or saturated zones associated with the proximity of water bodies. In addition, the high permeability derived from extensive aquifers may require complementary measures to control groundwater-level drawdown and prevent washouts in excavations.

Seismicity in Gallur is assessed as notable, with more than 50 events over 30 years and a maximum magnitude (Mmax) of 4.8, which implies the need to integrate seismic criteria into the structural design of buildings. Since the subsoil is not clayey, the risk of expansivity is ruled out. However, special attention should be paid to the possible presence of karstic phenomena, as karst has been identified in the area, requiring specific verification before defining the type of foundation. The main constraint focuses on the interaction between the appreciable seismicity and any possible karst processes.