Anchor reinforcement motorway tunnel

St. Gallen, Switzerland
Federal Road Office Astra
Geobrugg AG
Protected object
System height
Initial situation



Some of the tie bars in the vicinity of a gravity wall have corrosion problems. These corrosion problems can result in tie bars suddenly fracturing – brittle fracture – and flying into the clearance gage profi le of the adjacent freeway lane. The aim of an elaboration was to brake the tie bars at a relatively short distance, preventing them from penetrating the lane space. Geobrugg’s answer comprises a high-tensile steel wire mesh stretched in front of the 64 tie bar heads and provided with four braking rods, two at the top and two at the bottom. The ingenious interaction of this mesh and the specially designed braking system permitted a reduction in kinetic energy of up to 30 kJ for a defl ection of only 40 cm. Use is made here of the specifi c material properties of the utilized steel (very high dynamic- plastic deformation capability).

Your local contact

Ivo Naef
Ivo Naef
Sales Manager Safety Solutions
Impact Protection
Geobrugg AG
Aachstrasse 11
8590 Romanshorn / Switzerland