Gallery structures have long been used to protect vulnerable sections of road from the threat of rockfalls but a new system from Geobrugg offers to add to the level of protection. Rockfall-X is a damping system that has recently been installed for the first time between Weesen and Amden in Switzerland following successful field tests. The system aims to protect the gallery roof and reduces the static loading compared to conventional gravel damping systems.
The system uses specially constructed damping modules, filled with cellular glass ballast produced from recycled glass, and Tecco high-strength steel wire mesh which is installed horizontally over the damping material. It is designed to dissipate the impact energy in an elastoplastic manner.
According to Geobrugg, the significantly lower unit weight of the overall system allows the volume of damping material to be increased by a factor of between six and eight without placing additional load on the gallery structure.
The low weight of the modular system makes installation and repair work easier. After each rockfall, boulders can be removed so the system components can be checked. Even in the event of a major incident, only the top 100mm to 200mm of damping material needs to be replaced.
The gallery roof can also be greened over without impairing its protective function, but Geobrugg says that trees should not be planted for safety reasons.