Geotechnical study in Lezuza

In Lezuza, the geological substrate is dominated by the frequent presence of gypsum, anhydrite and salts (47,09%), together with limestones, dolomites and marbles (26,54%). In general, these materials provide a medium to high bearing capacity for foundations, although gypsum-bearing soils may undergo dissolution processes, increasing the risk of subsidence or instability beneath shallow supports. It is essential to carry out a detailed investigation to identify possible zones of dissolution and to select the foundation type appropriately, avoiding the most altered levels. The occasional presence of gravel and compact sands facilitates shallow foundation solutions, but in areas with fine sands and silts, as well as hard clays, specific characterisation will be necessary to assess the uniformity of the support.

Seismic activity in Lezuza is very low (5 events in 30 years and maximum magnitude of 2.2), so seismicity does not constitute a relevant limiting factor in structural design. However, the geological context, with a clear predominance of materials susceptible to karstification, requires karst verification before carrying out foundations, as the existence of cavities or underground conduits can seriously affect the structural safety of the building. The non-clayey substratum eliminates the risk of expansivity. The key factor governing geotechnical studies in Lezuza is the possible presence of karstic and dissolution processes associated with gypsum and salts, which must be assessed in detail through specific investigation.