Geotechnical study in Montornès del Vallès

In Montornès del Vallès, slates and schists predominate, alternating with fine sands, silts and granular materials such as gravels and compact sands. The secondary presence of granite, gneiss and sandstone formations, conglomerates and flysch provides a geotechnically diverse foundation, although in general low-permeability soils are encountered. Bearing capacity is usually adequate in the gravel and compact sand horizons, enabling shallow foundations, whereas in areas of silts or slates a more detailed study is recommended to prevent differential settlement.

Seismicity in the area is very low, with only 5 events in 30 years and a low maximum magnitude, so seismic risk is marginal and does not condition the structural design. There are no records of karstification or problems associated with expansive clays, since the non-clayey substrate eliminates this type of risk. In conclusion, the main limiting factor is generally related to lithological variability and the differential behaviour between fine and coarse soils, recommending specific reconnaissance campaigns for each project.