ROCKFALL-X™ G damping system (GeoBrugg) makes rockfall protection galleries even stronger
http://www.geobrugg.com/contento/Portals/35/media/Download-Brochures/Geobrugg_AG_Rockfall-X_en.pdf
http://www.geobrugg.com/contento/Portals/35/media/Download-Brochures/Geobrugg_AG_Rockfall-X_en.pdf