Upgrading the Arlberg tunnel to current safety standards. (April 2015)

• Record Type: Journal Article
• Authors: Sturm, Peter J.; Bacher, Michael
• Is Part Of: Tunnelling and underground space technology. Volume 48(2015)
• Page Start: 140
• Page End: 146
• Publication Date: 2015-04
• Subjects: Road tunnel -- Upgrading -- Ventilation system -- High-pressure water-mist system -- FFFS -- TERN; Tunneling -- Periodicals; Underground construction -- Periodicals; Tunnels -- Periodicals; Underground areas -- Periodicals; 624.193
• DOI: 10.1016/j.tust.2015.02.006
• Languages: English
• ISSNs: 0886-7798

Abstract

Graphical abstract: Highlights: Upgrading of existing tunnels to current safety poses a big challenge. Using fresh air ducts in transverse ventilated mined tunnels is a novel solution. Such a solution requires massive changes in ventilation. Additional structure protection is needed for protection of the egress way in case of a fire. Usage of high pressure water mist systems for protection of human live and structure. Abstract: Austrian road tunnels within the Trans-European Road Network (TERN) must fulfil the requirements of the Directive 2004/54/EC (European Commission, 2004) not later than April 2019. This regulation has to be applied to all tunnels in the TERN with a length of more than 500 m, whether they are in operation, under construction or at design stage, and aims at ensuring a minimum level of safety for road users. One of the main features of this directive is the requirement for providing an egress possibility to a safe environment every 500 m throughout the whole tunnel. The Arlberg road tunnel has a length of some 15.5 km and is in operation for more than 35 years. It is a single tube tunnel operated with bi-directional traffic, but carries a quite low traffic volume. Hence, the construction of a second tube is not really cost effective. Currently the tunnel is equipped with a transversal ventilation system with remotely controlled smoke extraction dampers providing smoke extraction every 100 m. The maximum distance between egress possibilities to a save environment is some 1500 m. Due to the high costs of a construction of a second tube or a parallel running escape gallery, a novel solution was found. The existing fresh air duct will be used as safe escape way between the existing egress possibilities. This solution has big impacts on the ventilation system and on the requirements for thermal structure protection of the new egress ways, i.e. the fresh air duct. In order to overcome this problem, massive changes in the ventilation design have to be performed, accompanied by the installation of a high-pressure water-mist system for structure protection.