The Strait of Gibraltar represents an exceptional geotechnical challenge due to the combination of high marine depths, seismic activity, and geological complexity. Geotechnical conditions include poorly consolidated sedimentary formations, active faults, and materials of low competence in some sections.
The main challenges include:
• Extreme hydrostatic pressure: With depths reaching up to 300 meters, the hydraulic loading conditions on the tunnel lining are significant, requiring high-strength materials and a robust waterproofing system.
• Seismic activity: The region is located on a tectonic boundary between the Eurasian and African plates, necessitating advanced seismic designs and energy absorption systems at tunnel joints.
• Support and excavation: The use of double shield TBMs or combined drilling and blasting systems is anticipated in more competent zones. The use of real-time geotechnical monitoring and modeling systems will be crucial for managing the behavior of the rock mass.
The project's success will depend on the application of innovative technologies in geothermography, seismic detection, and flexible linings that allow adaptation to changes in the geomechanical conditions along the alignment.