Geotechnical study in Gilet

In Gilet, the predominant substrate is composed of limestones, dolomites and marbles, together with significant percentages of sandstones, conglomerates, flysch and layers of fine sands and silts. These materials provide, for the most part, a high bearing capacity, which favours solutions involving shallow foundations, although heterogeneity in the grain size distribution may require detailed studies to avoid differential settlements. The presence of permeable and productive aquifers represents an advantage in terms of natural drainage, but it also requires supervision during foundation execution, especially near gravels, compact sands or areas close to bodies of water in order to prevent moisture problems in basements or excavations. Even though the risk of gypsum and salts is localised, it implies paying attention to dissolution phenomena under certain hydrological conditions.

Seismic activity in the municipality is moderate, with 27 registered events over three decades and a maximum magnitude of 3.4, which places Gilet in an area of low seismic hazard, without this implying any exceptional requirement in the usual structural design. As no predominant expansive clays are detected, the risk of expansivity is ruled out by the rocky composition of the substrate. It is crucial to highlight the importance of karst in this setting: prior verification of the development and continuity of karst cavities is mandatory before undertaking foundation projects, as this is the main factor to consider in the local geotechnical analysis.