Geotechnical study in Santa Susanna

In Santa Susanna, slate and schist prevail as substrates, followed by granite, gneiss and other igneous rocks, with an occasional presence of gravels, compact sands and some limestones or dolomites. These materials are typically competent, with adequate bearing capacity for shallow foundations, provided they are founded on the rock substrate. The formations are mostly impermeable or of very low permeability; however, the local presence of shallow aquifers may influence the hydrological behaviour of the ground, which is why it is essential to determine the groundwater table in the geotechnical study.

Seismicity in Santa Susanna is very low, with only 2 events reported over 30 years and a maximum magnitude (Mmax) below 2.5, so it does not represent a significant concern for structural design. The absence of clayey materials in the natural substrate rules out risks associated with expansive clays, and no karstic zones have been identified within the municipal term. Thus, the main constraint is linked to the competence of the rock substrate and to the assessment of possible shallow groundwater levels during the design and execution phases of foundations.