Estudio geotécnico in Calonge and Sant Antoni

In Calonge i Sant Antoni, the subsurface is formed mainly by compact gravels and sands, accompanied by slates, schists, and a considerable percentage of granite, gneiss and igneous rocks. These lithologies favour a high bearing capacity, allowing the execution of shallow direct foundations in most cases. Fine sands and silts appear occasionally and require specific attention in projects where they constitute the near-surface horizon, to avoid problems caused by differential settlement. Permeability is low in most strata, although shallow aquifers may exist in certain areas.

Seismicity in the municipality is moderate, with 21 events recorded over the last three decades and a maximum magnitude of 2.5, a value that does not imply relevant constraints for structural design. Analysis of the subsoil rules out risks associated with expansivity, since the materials are non-clayey, and no karstic areas are identified that could affect the stability of the foundations. The main factor to consider in local geotechnical studies is ground heterogeneity and the precise identification of horizons of low compaction or loose materials, to ensure the safety and functionality of the designed foundations.