RISKS AND HAZARDS CAUSED BY GROUNDWATER DURING TUNNELLING: GEOTECHNICAL SOLUTIONS USED AS DEMONSTRATED BY RECENT EXAMPLES FROM TYROL, AUSTRIA

Abstract

As demonstrated by recently excavated reconnaissance tunnels, uncontrolled water ingresses frequently pose a risk to tunnels and the tunnelling crew despite ever-improving tunnelling methods. This is regardless of the type of rock encountered and can result in significantly increased construction costs.