Geotechnical study in Melilla

In Melilla, the geotechnical study reveals the significant presence of fine sands and silts, together with an important carbonate substratum made up of limestones, dolomites and marbles. As these materials are common, they condition the foundation recommendations: granular soils may exhibit variable bearing capacity and potential for differential settlements, whereas carbonate rocks usually provide good support provided that the degree of alteration is controlled. Granite, gneiss and igneous rocks appear only occasionally and can represent excellent foundation bases, although it is necessary to assess their continuity and fracturing. Urban anthropogenic fills, although in the minority, require particular attention in order to rule out their direct use as a support level.

The seismic analysis shows high seismicity in Melilla, with more than 150 events and an Mmax of 6.8, which implies that the design of the foundations and structures must be adapted to this hazard through specific solutions. Since no evidence of karst or indications of expansive soils has been detected, these factors do not influence the development of the works. The main geotechnical constraint for any project in this municipality is therefore seismic risk, which must be addressed in all stages of structural design.