In Ehrenhausen in southeastern Austria, south of Graz, an embankment was destabilized by heavy rainfalls. A landslide occurred near the train station along the railway tracks of the Suedbahn, affecting an approx. 200 m long section of the embankment. Parts of the failed embankment buried the tracks so that about 5,900 m³ of the slope had to be removed.
Afterwards, the unstable slope was stabilized by installing soil nails up to a depth of 12 m and by installing high strength steel mesh to contain the slope material. The Suedbahn railway track that had been closed due to the landslide had to be reopened for railway traffic as soon as possible, so the slope had to be stabilized within a very tight schedule.
Protective grille and rockfall protection fences needed
In total, about 6,850 m² of embankment had to be stabilized, and 517 m long rockfall protection fences had to be built. In the soaked unstable slope, stabilization using soil nails could only be carried out manually and using a walking crane.
The soil nails ensured an efficient use both for mechanized installation using the walking crane and for manual installation. Thanks to the flexible coupler system and the comprehensive range of drill bits, the soil nails could be directly adapted to the prevailing geological conditions.
The stabilization of the embankment required 1,170 R32-320 kN soil nails with a total length of 7,400 m, 50 R38-550 kN soil nails with 370 m total length and 130 R51-660 kN soil nails (total length of 900 m). For the foundation of the rockfall protection structures, 185 bar anchors with a total length of 400 m were used.