Geotechnical study in Pollença

In Pollença, soils formed by fine sands and silts predominate, which significantly conditions bearing capacity, as these materials exhibit variable mechanical properties and generally a low to medium resistance for foundation construction. It also highlights the significant presence of gypsum, anhydrite and salts—materials that require a detailed analysis due to the risk of dissolution and possible subsidence, especially in contact with masses of water. Although limestones and dolomites occur in a smaller proportion, their localised presence could locally modify the foundation design strategy.

Seismicity in the municipality is very low, with only one significant event over 30 years and a low maximum magnitude, which implies a minimum requirement at structural level in this respect. However, the possible presence of karst associated with carbonate formations requires thorough verification before designing any foundation, as there may be cavities or unstable soils of karst origin. The absence of clayey soils eliminates the risk of expansiveness as a conditioning factor. Therefore, the most determining factor for the geotechnical study in Pollença is the interaction between soluble materials (gypsum, salts) and the possible presence of karst.