A9 Full extension Gleinalm tunnel - Planning of operating and safety-related facilities and of the ventilation system

Project duration: 2010 - 2012

Location: Styria, Austria

Client: ASFiNAG

Description of project

Originally, the Gleinalm tunnel consisted of only one tunnel tube and was operated as a two-way traffic tunnel. The existing and following first tunnel tube is an approx. 8.3 km long west tube and was built between the end of the 1970ies and the beginning of the 1980ies. In the course of this project, the construction of a second tube and the reconstruction of the first tube were planned.

For the ventilation of the middles section of the existing and the new tunnel tube are two vertical ventilation shafts available, which are located on the west of the existing tube. They lead to two cavern stations (North and South), which contain the exhaust air fans for the middle ventilation sections as well as other operating and safety-related facilities. Additionally, for both tubes, in the area of the northern and the southern portal, there are engine houses for the exhaust air fans of the ventilation sections of the portals North and South. In the scope of the planning process, the ventilation system should be adapted to the specifications of the RVS 09.02.31. Basically, the ventilation system is a semi-transversal exhaust air ventilation. The longitudinal air flow in the driving area is controlled by means of FU-regulated jet fans. The scope of service included the dimensioning of the tunnel ventilation system for normal operation and in case of an accident. Furthermore the ventilation of the escaping routes and the fresh air supply of the caverns North and South, which are necessary for the ventiliation and the climatisation of the e-rooms and the exhaust fans, was planned.

The temporal construction process was the following:

New tunnel tube (East tube or second tube):
At that time the existing tube was operated for bi-directionsal traffic.
General reconstrcution of the existing tube (Western tube or first tube): The overall tarffic of the Western tube was redirected into the Eastern tube, which was operated for bi-directional traffic during the general reconstruction phase.
Completion: After the general reconstruction of the Western tube, both tubes are operatd for uni-directional traffic.

Basic data of the tunnel:

Number of tubes: 2
Traffic routing: uni-directional
Tunnel length: new tube: 8.291 km; existing tube: 8.321 km
Number of ventilation sections: 4 for each tunnel tube
Ventilation system: semi-transversal exhaust air ventilation and jet fans

Special features of the tunnel:

Ventilation system: Special operating mode of the ventilation of the new tube during the reconstruction phase of the existing tube