Geotechnical study in Artà

In the municipality of Artà, the predominant subsurface materials are limestones, dolomites and marbles, to which are added significant areas containing gypsum, anhydrite and salts, as well as layers of fine sands and silts. This type of carbonate rocks, with evaporitic intercalations, generally exhibits good bearing capacity, allowing direct foundations to be designed in many cases, although it is essential to identify the continuity and alteration of the strata. The occasional presence of expansive clays and hard clay and marl zones is limited, which reduces the likelihood of encountering problematic soils for direct support. Nevertheless, gypsum, anhydrite and salts imply a potential risk of dissolution that must be assessed carefully, as they can lead to subsidence or localised collapses.

The region is characterised by very low seismic activity, with only a single recorded event in 30 years and a maximum magnitude of 1.8, which makes it possible to rule out seismicity as a relevant factor in structural design. It is important to emphasise the presence of a karstic environment, which requires a thorough verification of cavities and possible voids before carrying out any foundation, with the aim of avoiding stability problems in the future. The non-clayey substratum rules out the existence of problems associated with expansivity. Thus, the main geotechnical constraint in Artà is related to the possible presence of karst and the risk of dissolution processes in evaporitic materials.