Semmering base tunnel

Around 27 kilometres in length, 18 years of construction time and challenging geological conditions

Project description: 

The 27.3 km long two tube railway tunnel is an essential part of the Baltic-Adriatic Axis (TEN corridor) in Austria and connects Lower Austria with Styria. After commissioning in 2026, the journey time from Vienna to Graz will be shortened by 30 minutes. The tunnel construction work is essentially divided into 3 areas:

  1. Tunnel section Gloggnitz: The 7 km long tunnel will be excavated and blown up from two construction sites: From the tunnel portal in Gloggnitz towards Mürzzuschlag and from the Göstritz access shaft towards Gloggnitz and Mürzzuschlag.
  2. Tunnel section Fröschnitzgraben: With a length of about 13 km, this middle section is the longest. Tunnel driving is carried out in two directions from the 2 access shafts that are more than 400 m deep. The approximately four-kilometer long section towards Mürzzuschlag is excavated and blasted, the approximately nine-kilometer long section towards Gloggnitz is created with two tunnel boring machines. The excavated material is taken to the nearby Longsgraben landfill. The cavern at the foot of the shaft will be converted into an underground emergency stop.
  3. Tunnel section Grautschenhof: The approx. 7 km long section will be excavated and blasted via two access shafts with two tunnel drives each -one per tube -in the direction of Mürzzuschlag and in the direction of Fröschnitzgraben.

Further information can be found here

GEODATA services:

We were commissioned by ÖBB Infra to carry out the geotechnical measurements and the control surveys. The extensive scope of services includes the supply of geotechnical instrumentation and data acquisition, the measurement execution including optical 3D displacement measurements and gyro measurements. In addition, geophysical measurements are carried out underground to investigate and evaluate karst-prone mountain sections.


Location: Lower Austria/Styria, Austria

Client: ÖBB Infrastruktur

Performance period: since 2014