Geotechnical study in San Juan del Puerto

In San Juan del Puerto, the predominant bedrock is composed of limestones, dolomites and marbles, accounting for more than 60% of the ground, which provides excellent bearing capacity conditions for shallow or deep foundations. Slates and schists, present occasionally, may require a local assessment due to their lower capacity and possible superficial alteration. Fine sands, silts and granular materials appear in scarce amounts and, although they improve drainage locally at times, they do not constitute the dominant geotechnical horizon. This lithological configuration favours a safe foundation; however, it is recommended that the presence of any possible superficial aquifers is analysed, given the limited permeability of many of the formations.

Seismic activity in San Juan del Puerto is very low, with only 2 events in the last 30 years and a maximum magnitude of 3.1, meaning that seismicity does not represent a relevant limitation for structural design. The absence of clayey strata rules out expansivity risks, which simplifies the selection of the foundation system and reduces the likelihood of differential movements due to swelling or shrinkage. The main geotechnical constraint will therefore be more closely linked to the possible presence of superficial aquifers and the type of local rock, which requires specific characterisation at each site.