Geotechnical study in Font-rubí

In Font-rubí, the predominant soils correspond to sandstones, conglomerates and flysch, accompanied in a smaller proportion by compact gravels and sands. These lithologies, of granular nature and with moderate to low cohesion, generally exhibit good bearing capacity, with the exception of locally altered zones or areas where less competent materials are present on a spot basis. The occurrence of limestones, dolomites and marbles, although less frequent, may imply the presence of a competent substrate suitable for direct foundations when its continuity is verified. The low permeability typical of these formations minimises differential settlement due to leaching; however, if there are deep aquifers, it will be necessary to assess the possible effect on the balance of the water table under load.

Seismicity in the municipality is very low, with only about 3 events in the last 30 years and a maximum magnitude of 1,6, which implies a negligible influence on structural design. However, the presence of carbonate materials implies a possible development of karstification; therefore, even if only occasional, before defining the foundation any cavities, sinkholes or underground instabilities must be ruled out. The risk of expansivity is ruled out thanks to the absence of clayey soils, leaving as the main constraint the need to verify the possible existence of karst processes or local instability associated with the limestones and dolomites.