Geotechnical study in Adra

In Adra, formations of slates and schists predominate, followed by limestones, dolomites and marbles. These materials typically provide good bearing capacity, although in areas with fine sands and silts, albeit infrequent, the strength may be reduced locally. Permeability is generally low, limiting infiltration, but shallow aquifers may exist in certain areas. In this context, the choice of foundation system will depend on the location, with direct foundations being the usual recommendation except in areas where less competent material outcrops.

Seismicity is notable in the area, with 101 events over 30 years, although of moderate magnitude (Mmax 3.9), so seismic actions must be taken into account in structural calculations. Given the significant presence of carbonate formations, it is essential to carry out a specific check to rule out any karst-related effects before executing the foundation, as this condition could seriously affect ground stability. The non-clayey substrate eliminates the risk of expansivity as a relevant factor.