K36 Lammschlucht Gorge, Rehabilitation and Maintenance

In the Lammschlucht Gorge rock fall, block fall and landslides are common and engineering structures are in need of repair. Before the start of the 2nd phase construction works in 2010 there was a shallow spontaneous landslide on the edge of the road on the valley side, which was rebuilt with a back anchored supporting wall (length=35m). As part of the concept for interim measures the unstable pieces of rock, artificial rock slopes, geo-logical foundations of the engineering structures and several block stone walls were secured with back anchor shotcrete or concrete. The areas exposed to rock fall were equipped with a safety net. The sandstone arched bridge at the end of the gorge was retrofitted using steel clasps and back anchor foundations. In the Unter Tänndli area the edge of the road on the valley side was secured with a bored pile wall and a head beam (length=50m). The sealing, the supports, the natural stone walls and the concrete of the engineering structures were repaired.

Main Data

  • Shotcrete: 150 m3
  • Concrete: 210 m3
  • Swiss-Gewi-Anchor: 1,400 m
  • Rock fall safety net: 70 m
  • Bored piles d=0.9-1.0: 220 m


Lucerne Canton Construction Directorate, Office for Transport and Infrastructure, Road Inspectorate (KSI) / Construction Department


IUB Engineering AG

Construction period


Construction costs

CHF 2.5 million

Scope of services

  • Pre-project, construction project, tendering, implementation
  • Statics
  • Site supervision