Brenner Basistunnel – Vortrieb im unmittelbaren Nahbereich von Bestandsbauwerken im Baulos Tulfes–Pfons

Abstract

This report deals with tunnelling over and under existing tunnels with unreinforced concrete linings and tunnelling under an existing tunnel only supported with shotcrete. The uppermost task was to avoid damage to the existing tunnel and this could be fulfilled through carefully staged advance steps, technically correct construction by the contractor and a dense observation network. The experience tunnelling over an existing tunnel supported only with shotcrete shows that despite slight deformation, cracks and spalling occurred to the shotcrete support layer of the tunnel beneath. This damage did impair the serviceability of the support layer although the structural safety of the tunnel was never in danger. The impairment of the serviceability was temporary and could be remedied by installing overhead protection. In the long term, repair measures were necessary to the support layer in zones with poor geological conditions.

Conventional excavation of the emergency stop Innsbruck at the Brenner Base Tunnel: Approach, measures and experiences

“…Construction work in the area of the Innsbruck emergency stop station got underway in the spring of 2015 and is part of the main construction lot H33 Tulfes-Pfons. The access tunnel to the Ahrental transverse cavern and the cavern itself were constructed beforehand [2].…”