Geotechnical study in Erandio

In Erandio, sustrates composed of sandstones, conglomerates, flysch predominate, as well as limestones, dolomites and marbles, which suggests the widespread presence of competent soils for foundations. Fine sands and silts appear only occasionally and may exhibit some locally localised compressibility, whereas man-made fill and masses of water are infrequent but should be considered in detailed studies due to their heterogeneity or possible differential settlements. The priority presence of hard materials generally provides good bearing capacities for buildings and civil engineering works.

Seismicity in the area is notable, with 94 events recorded over the last 30 years, although with a moderately low maximum magnitude (Mmax 3.7), which implies that seismic actions must be taken into account in geotechnical studies, particularly for large-scale projects. The non-clayey substrate rules out the presence of expansivity risks, favouring the durability of the foundations. The most relevant constraint in Erandio will be the precise characterisation of the supporting materials, especially in view of the possible presence of occasionally compressible or heterogeneous ground.