Geotechnical study in Vallirana

In Vallirana, the dominant materials are limestones, dolomites and marbles, representing most of the subsoil, followed by a significant presence of gypsum, anhydrite and salts, while sandstone, conglomerates and flysch appear occasionally. These types of strata generally provide a good bearing capacity for buildings, although the presence of gypsum and salts may entail a risk of dissolution processes that could affect the stability of the foundations. A detailed analysis is essential to select the most suitable foundation depth and type, given the varying characteristics of these materials and the moderate permeability of the existing aquifers.

Seismic activity in Vallirana is moderate, with 19 recorded events over the last 30 years, and a low maximum magnitude, so seismic risk does not represent a severe constraint in structural design. The non-clayey substrate rules out risks of expansivity, favouring the volumetric stability of the ground. However, the potential presence of karst associated with the limestones makes it necessary to carry out a specific verification of cavities before choosing the foundation solution, since these phenomena can compromise the safety and durability of the building.