Geotechnical study in Jaca

In the municipality of Jaca, the subsoil is composed mainly of limestones, dolomites and marbles, together with a significant presence of sandstones, conglomerates and flysch. This rocky substrate promotes good bearing capacities, allowing direct foundations in many cases, provided that the uniformity and compactness of the materials are respected. The occasional presence of fine sands and silts means that, in specific areas, it is necessary to assess their suitability as a foundation support material, as they may exhibit lower medium to low resistance under poor compaction. In general, the low permeability of the predominant formations limits the migration of groundwater, which additionally stabilises the bearing capacity.

As regards geotechnical risks, seismic activity in Jaca is moderate, with 35 events in the last three decades and a maximum magnitude of 3.2, so seismicity has a tangible although contained influence on structural design. On the other hand, the karst component associated with the limestones requires careful verification before proceeding with foundation works, as the presence of voids or cavities can seriously affect stability. In addition, since the substrate is non-clayey, there is no risk of expansivity, which supports the durability of the foundation solutions. Thus, the main variable to control in the geotechnical study of Jaca is the possibility of karst processes in the ground.