The Prenner Pedestrian Tunnel is located in the centre of Ischgl, Austria and ensures a direct connection of the parking garage in Ischgl's centre with the 3-S Pardatschgrat gondola. The mined part of the tunnel included in this contract is 130 m long and has a cross section of approx. 26 m².
The owner, Silvrettaseilbahn AG, awarded the contract for the tunnelling work to ÖSTU-STETTIN Hoch- und Tiefbau GmbH, Austria. Due to the fact that the tunnel is located directly underneath the densely developed town centre of Ischgl, tunnel work had to be carried out very carefully.
Moraines containing blocks up to the size of houses
The tunnel portal had to be elaborately stabilized in advance using R32-250 Ø hollow bar anchors and shotcrete. The moraine material in the area of the jobsite is loose and partly contains blocks the size of houses. To stabilize the tunnel advancement, PANTEX 3- and 4-bar lattice girders were installed.
Structural work had been completed before the 2015/16 winter season so that the tunnel could be opened for pedestrians. Once completed, the tunnel will also be equipped with two escalators for providing additional comfort to ski-tourists.