Geotechnical study in Zafarraya

In the municipality of Zafarraya, substrates of limestones, dolomites and marbles predominate. These materials generally offer excellent bearing capacity and allow the execution of shallow foundations, except for specific, isolated cases. Occasional levels of expansive clays and formations of sandstone and flysch represent a smaller proportion and, although they may influence local conditions, they do not usually significantly determine the choice of foundation type for most projects. The low permeability of the main materials limits the occurrence of deep aquifers, although surface formations with water retention may exist.

Seismicity in Zafarraya is considered moderate, with 46 recorded events in the last 30 years and a maximum magnitude of 2.8, implying limited seismic risks from a structural perspective. It is relevant to note the presence of karst linked to the domain of limestone and dolomitic rocks; therefore, it is essential to verify the existence of cavities, voids and dissolution phenomena before designing any foundation. The absence of an clayey substrate eliminates the risk of expansivity, placing attention on karst processes as the main geotechnical factor to be controlled through a specific geotechnical study prior to construction.