K36 Lammschlucht Gorge, Unter Tänndli Retaining Wall

The Unter-Tänndli retaining structure on the valley side is in poor condition and tilts. It supports the K36 cantonal road (Schüpfheim - Flühli) on the valley side coming up from the gorge. The retaining wall was probably erected in 1956 when the road was widened. An open bored pile wall consisting of reinforced bore piles and top plates was installed to secure the retaining wall on the valley side with respect to the road and the existing em-bankment. The anchoring depth of the bored piles was selected to ensure com-plete anchoring in the deep rock. The bored piles are monolithically connected with the top plates. The crash barrier was mounted onto the guide wall.

Main Data

  • Bored piles d=0.9-1.0 m: 220 m
  • Top plates: 50 m
  • Concrete top plates: 75 m3


Lucerne Canton (vif – Transport and Infrastructure Department), Building Section


IUB Engineering AG in consortium

Construction period


Construction costs

CHF 440,000

Scope of services

  • Preliminary project
  • Construction project
  • Tendering
  • Implementation project
  • Local site supervision