Groundwater in the Perthus Tunnel: feedback after excavation

• Main Authors: Antonio Dematteis, Riccardo Torri, Bertrand Chereau, Michel Ducrot
• Format: Article
• Language: English
• Published: PAGEPress Publications 2021-06-01
• Series: Acque Sotterranee
• Subjects: groundwater; tunnel excavation; monitoring; thermal springs; drawdown hazard
• Online Access: https://acquesotterranee.net/index.php/acque/article/view/518

This work presents the experiences gained during the construction of the Perthus high-speed railway tunnel (8.4 km long), as regards water inflow management, analysis of the impact on surface-waters and groundwater, monitoring of piezometers and water quality control, soil injections. The excavation met granodiorites, schists, diorites, gneisses, black schists and coarse river deposits (pebbles and blocks) near the north portal. Some important tectonic structures, and associated groundwater flow, were also crossed. Finally, a geothermal study on the hydrothermal springs Le Boulou, which were not impacted, is presented.