Geotechnical study in Quintanilla de Onésimo

In Quintanilla de Onésimo, carbonate materials such as limestones, dolomites and marbles predominate, which make up approximately 60% of the substrate. These types of soil usually offer good bearing capacities and are suitable for shallow (direct) foundations, although the occasional presence of gypsum, anhydrite and salts implies an additional risk of dissolution that may cause subsidence. Furthermore, the aquifers in the area are extensive and highly permeable, so it is essential to analyse in detail the hydrological behaviour before sizing the foundation.

The municipality has a high level of seismicity, with more than 150 recorded events over 30 years and a maximum magnitude of 4.7, which requires specific consideration in the structural design of buildings. Karst development is a key constraint that must be examined exhaustively before foundation works, as it may lead to instabilities or unexpected underground voids. The absence of clayey substrates rules out the risk of expansivity, so the main geotechnical constraints in Quintanilla de Onésimo are seismic activity and the possible occurrence of karst processes and dissolution of gypsum.