Geotechnical study in Barcelona

In Barcelona, the dominant presence of compact gravels and sands is observed, accompanied by overconsolidated clays and marls, as well as slates and schists, forming firm, high-strength subsoils. The gravels and sands provide adequate bearing capacity for various types of shallow foundations, whereas the hard clays and overconsolidated marls make it possible to carry out direct foundations, subject to normal precautions regarding potential settlements. The occasional presence of fine sands and silts requires particular attention with respect to consolidation and possible under-excavations, but in general the lithological variety allows efficient technical solutions to be proposed for building and civil engineering works.

Seismicity in Barcelona is very low, with only 5 events over 30 years and a maximum magnitude of 1.6, which implies a practically negligible seismic risk for structural design. Furthermore, as the subsoil is non-clayey, the problem of expansive soils is ruled out, and no karstic phenomena are reported in the area. In conclusion, the main focus of the geotechnical study in Barcelona should be on the local identification of cohesive and non-cohesive soils and on an appropriate characterisation of the groundwater table level and permeability, with a low incidence of other major geotechnical constraints.