Geotechnical study in Purchena

In Purchena, soils formed by slates and schists predominate, representing more than 70% of the geotechnical substrate. These materials usually show adequate bearing capacity for shallow foundations, although it may be necessary to analyse the orientation and foliation of the rocks to avoid risks associated with planes of weakness. Fine sands and silts, present occasionally, require caution due to their lower cohesion and possible subsidence under structural loads. Limestones, dolomites and marbles, although not very abundant, could provide good mechanical parameters in localised areas, provided that phenomena associated with their nature have been ruled out.

Seismicity in the municipality is moderate, with 28 events recorded over the last 30 years and a maximum magnitude that does not exceed significant values (Mmax 3.6), so seismic risk does not constitute the main limitation for structural design. It is important to note the presence of calcareous and dolomitic formations with potential for karst, which makes it necessary to carefully check the existence of cavities or karstic phenomena before determining the final foundation. The fact that the site is underpinned by a predominantly non-clayey substrate eliminates the risk of expansive behaviour. Therefore, the main geotechnical constraint in Purchena lies in the karst analysis in areas where carbonate materials crop out.