Maintenance of drainage systems. New problem in the sustainability of tunnels in calcareous terrains
- Carreteras Magazine Nº 213 - Mayo/Junio 2017
César FERNÁNDEZ-NESPRAL
Jefe de Demarcación de Carreteras en Asturias. Ministerio de Fomento
Pedro R. SOLA
Professor Master in Tunnels. Spanish Association of Tunnels y Obras Subterráneas (AETOS)
Carlos S. OTEO
Professor Master in Tunnels. Spanish Association of Tunnels y Obras Subterráneas (AETOS)
ABSTRACT
Tunnels in calcareous terrains with large aquifers are subject to solid carbonate deposits that increase in volume and resistance, obstructing the drainage and penetrating into the intrados of the tunnel lining. As a result, the annual maintenance costs increase by more than 20%. If no action is taken, both the service levels (hydroplaning and lower friction coefficient) and the reliability of the tunnel lining (sagging paving) are undermined. To improve this situation, the international experience in both the inspection and maintenance strategies and in the design recommendations should be followed.
KEYWORDS
Tunnel, Maintenance, Drainage, Calcareous terrain, Operation, Sustainability, Service level.