Geotechnical study in Lliçà de Vall

In Lliçà de Vall, the dominant subsoil is mainly composed of sandstones, conglomerates and flysch, which make up around 69% of the ground, accompanied by gravel and compacted sands in a significant proportion. These materials exhibit good mechanical properties, which facilitates a high bearing capacity and enables the execution of conventional shallow foundations in most cases. The occasional presence of fine sands and silts suggests that it is important to carry out adequate sampling to rule out pockets of non-compact material that could compromise the stability of the foundation.

Seismicity in the municipality is very low, with no significant records of activity or notable magnitudes, so it does not represent a factor to consider in structural sizing. With regard to expansiveness, although there are expansive clays in a lower proportion and localised in specific areas, the overall risk for typical buildings is moderate; however, their point-by-point identification is recommended during the geotechnical investigation campaign. The main constraint in the area is related to the local heterogeneity of the soils and the need to validate the bearing capacity at specific points in the ground.