Tunnel Sous la Trême, local road H189, Bulle

Bulle bypass via local road H189: Two-lane road tunnel in loose rock. Cover 3.5 m - 10 m in cultivated area, in ground water. Tunnel length 568 m, excavation cross section 129 m2, all-round sealing in pressure water, concrete inner ring and sub-ceiling.

Ground water lowered using a 30 m deep drainage gallery located below the tunnel, created from a slit wall shaft. Excavation and support in sub-sections with calotte bench and short ring closure time. Additional support throughout the tunnel length from jetting pillars and pipe umbrella pipes. Systematic support from HEB ring segments and shotcrete.

Map

Specific figures

Contract value

CHF 52.1 million

Construction period

2005 - 2009

Length

568 m

Total excavated surface

129 m2