Geotechnical study in Peroxa, A

In the municipality of Peroxa, A, the dominant substrate is composed of shales and schists, occurring overwhelmingly. This type of material has low permeability, which limits infiltration and natural drainage, although small near-surface aquifers may exist linked to local irregularities. Due to their competent and coherent nature, shales and schists typically provide a solid foundation, which increases bearing capacity and allows for shallow direct foundations in most cases, always considering surface fragmentation and the possible presence of weathering-related alterations.

Seismicity in Peroxa, A is high, with 200 events over the last 30 years and a maximum magnitude reaching 5; therefore, the structural design of buildings must incorporate appropriate anti-seismic criteria. The absence of karst and the non-clayey nature of the substrate rule out risks of expansivity or collapse due to dissolution. In summary, the main geotechnical constraint for the ground investigation will be taking into account local seismicity in combination with a detailed assessment of the degree of alteration of shales and schists.