Out of Sight

Cities throughout the world are benefiting from new underground road links. This article describes some of the new technology that is being used to construct, operate and maintain these underground links. Computerized drill rigs offer more accurate hole collaring, higher penetration rates and vast increases in overall productivity. Drill rod technology that was initially developed for the mining industry is being applied in tunneling to cope with the extra power delivered by new generation rockdrills. The rods feature different joint profiles with bigger cross-sections and special guides to reduce bending and breakage problems. Once a tunnel has been constructed, advanced lighting and safety systems are being installed. One system can detect stopped vehicles anywhere in the tunnel. A digital radio system that can broadcast emergency messages over loudspeakers and car radios, and provide radio coverage for emergency and maintenance services is also available. Lighting systems are incorporating light emitting diode technology that offer reduced cost and need less maintenance. In the area of tunnel maintenance, a sealing technology has been developed to prevent water ingress using a combination of accurate assessment and diagnosis, careful selection of appropriate resins and water reactive gels, and the use of advanced injection techniques.


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  • Accession Number: 01013366
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 17 2005 11:46PM