Bern / Forsthaus West, Waste Incineraton Plant, Lot 1 Main Connection

To connect the new waste incineration plant Bern/Forsthaus West wih the existing infrastructure of the old waste incineration plant Warmbächliweg, a passable utility line tunnel was built using the microtunnelling method. Four connecting structures were also constructed using the cut-and-cover method and in-situ concrete (junction shaft, valve chamber, distribution chamber with emergency exit and riser duct in the new Forsthaus West waste incineration plant). During tunnel driving it was necessary to cross under exisiting railway tracks, the cantonal road and gas station. The main connection includes a link to district heating distribution lines (feed and return with an outer diameter of 900 and 700mm), to the MV network (10kV) and telecommunications system as well as the supply of industrial water (inner diameter 125mm). The entire system is fitted with fire-resistant shielding from the neighbouring canal system and flooding protection. The electro-mechanical equipment includes electricity recipient centres, mobile telecommunications transmitters, fire cable, ventilation system as well as industrial water pump system and sump pumps.

Main Data

Main technical data: shaft structures

(Length x Width x Depth)

  • Valve chamber: 12.0 m x 7.0 m x 7.8 m
  • Entrance structure: 3.1 m x 4.1 m x 3.0 m
  • Junction shaft: 6.4 m x 4.4 m x 8.0 m
  • Distribution chamber: 6.3 m x 5.3 m x 11.5 m
  • Emergency exit: 1.5 m x 1.5 m x 0.7 m
  • Riser duct: 10.2 m x 6.0 m x 12.7 m
  • Mounting hole: 7.0 m x 1.3 m x 2.1 m
Main technical data:  microtunnelling
  • Nominal diameter:    3000 mm / 3600 mm
  • Pipe material:    reinforced concrete 300 mm
  • Length of pipe:    approx. 516 m
  • Covering:     min 5.0 m; max 14.0 m
  • Gradient:     min 3.0 ‰; max 30.7 ‰
  • Radii: horizontal 500 m, vertical 2000 m
  • Advance rate: approx. 12 m per day; max. 22 m per day; in 2-shift system
  • Geology: groundwater, silt, gravel, backwater sediment

Client

Energie Wasser Bern, ewb

Consultant

IUB Engineering Ltd in consortium

Construction period

2010-2013

Construction costs

Lot 1: CHF 15.7 Mio. of which special civil eng.: CHF 10.7 Mio.

Scope of services

  • Alternative study, preliminary project, detailed project for construction
  • Construction project
  • Tendering, bid evaluation
  • Project execution
  • Construction supervision