Geotechnical study in Anoeta

In Anoeta, limestones, dolomites and marbles predominate, which implies high bearing capacities that are generally favourable for shallow (direct) foundations. The occasional presence of granite and gneiss reinforces the ground’s competency, whereas horizons with gypsum, anhydrite and salts may entail localised dissolution risks in certain areas. Looser materials, such as fine sands and silts, occur in low proportions, so they rarely condition the structural support level.

Seismic activity is very low (1 event in 30 years, Mmax 1.9), which virtually eliminates this constraint from structural design. However, the possibility of karst-related phenomena associated with the frequent presence of limestones and gypsum requires careful verification of ground stability and homogeneity before founding. The risk of expansivity is ruled out due to the absence of predominantly clayey soils, and karst control is the main factor to be assessed in geotechnical studies in the area.