Geotechnical study in Noáin (Valle de Elorz)/Noain (Elortzibar)

In Noáin (Valle de Elorz)/Noain (Elortzibar), the dominant subsoil is made up of limestones, dolomites and marbles, which account for more than 84% of the soils. These rock materials provide excellent bearing capacity, making them suitable for shallow foundations and reducing the likelihood of settlement-related problems. On an occasional basis, it may be possible to find fine sands and silts, whose mechanical behaviour is less favourable, although their presence is limited in the local context. Overall, the site features formations with very low permeability, although the existence of shallow aquifers cannot be ruled out, which could require specific hydrogeological controls in projects that include deep excavations or basements.

The geotechnical study in this municipality is influenced by practically zero seismicity, with only 1 event every 30 years and a very low maximum magnitude (Mmax 2.1), which rules out the need for seismic conditions in structural design. Given the composition of the non-clayey subsoil, the risk of soil expansivity in the area is also ruled out. Similarly, there are no signs of karstic environments, which simplifies the assessment of risks associated with foundations. The main factor to consider will be the precise characterisation of the limestone formations and their possible interaction with groundwater, with conclusions generally being favourable for most buildings.