Schänis, State Road 17

State Road 17 / Gasterstrasse 8, 8718, Schänis, Switzerland
State Department for Underground Construction, Canton St.Gallen, Switzerland
Geobrugg AG, Geohazard Solution
Oberholzer Inc., Neuhaus, Switzerland
Protected object
Road, Building
Corrosion protection
Stabilized area
300 m²
Maximum slope height
15 m
Slope inclination
30 ° - 85 °
Initial situation

The area was formed by glaciers. With climate change, the rock underneath, molasse conglomerate rock, has become more unstable. During the past few years sections of rock, some with volumes of around 1 m³, became dangerously loose and were in danger of eminent fall onto the road, the building below and the neighboring pastures.

The Swiss State Agency for Forest and Natural Hazards immediately alerted the regional road inspectorate and political community to the potential risk.


Instable blocks of molasse conglomerate.


As a short term emergency measure Geobrugg worked with the regional road administration and a local contractor to stabilize the most critical rock sections with SPIDER® S3-130.

As a long-term solution that ensures safe driving conditions for daily commuting, an anchored system was installed. Along the deep chasms all along the molasse bar, three levels of anchors were drilled. The higher and lower levels were drilled to a length of 4 m while the anchors of the middle rows were drilled to a length of 7 m. These anchors were drilled to a grid that measures 2.15 m x 2.15 m.

The whole project from planning to final acceptance took only six weeks.

Your local contact

Roger Moor
Roger Moor
Country Manager Ost- und Zentralschweiz, Liechtenstein
Natural Hazards, Coastal Erosion Protection, Mining / Tunnels
Geobrugg AG
Aachstrasse 11
8590 Romanshorn / Switzerland
René Müller
René Müller
Country Manager Kantone AG BE BL BS FR GE JU NE SO VD VS
Natural Hazards, Mining / Tunnels
Geobrugg AG
Industriestrasse 21
5200 Brugg / Switzerland
Isacco Toffoletto
Isacco Toffoletto
Ticino Country Manager
Natural Hazards, Mining / Tunnels
Geobrugg AG Ticino
Stabile Cometal, via Pizzante 7
6595 Riazzino / Switzerland