Geotechnical study in Ayamonte

In Ayamonte, the dominant subsoil is formed mainly by slates and schists, followed to a lesser extent by fine sands and silts, with an occasional presence of limestones, dolomites and marbles. This mineralogical composition implies bearing capacities generally medium to low, and local heterogeneity may condition the selection of the foundation. In particular, the slates and schists, in addition to their low permeability, may require detailed studies to define the depth and type of strip footing or, where applicable, the feasibility of deep foundations when the aim is to pass through low-bearing levels.

Seismic activity in Ayamonte is moderate, with a record of 21 events over 30 years and a low maximum magnitude (Mmax 3.1), so seismic risk is limited in terms of structural requirements. There is no presence of karst or any significant risk of expansivity, since the subsoil is not clayey, which rules out problems associated with swelling or volumetric shrinkage. The low permeability of the materials is the main factor to take into account, as it may promote the rise of surface water or the development of shallow aquifers, which must be considered in foundation and drainage projects.