Devil’s Slide Tunnel

Project name

Devil’s Slide Tunnel




North America, California (US)


Primary Shotcrete Lining

Advantages and Benefits

  • Improved flexural strength of the shotcrete lining
  • Reduced wear on equipment · Improved worker safety
  • Eliminated corrosion
  • Removed the smoothing layer between the lining and waterproof membrane


BarChip Inc.


BarChip fibres

The Devil’s Slide tunnels, located on route 1 in San Metro County and excavated by road header using the New Austrian Tunnelling Method (NATM), are 1.26 km and 1.23 km long and pass under the mountain at depths up to 200 m. At the time of construction, macro synthetic fibres was widely used for ground support in #mining applications, but it had never been used in a civil road tunnel in North America.

After an extensive testing program, the project team were confident in macro synthetic fibres technology which ultimately delivered many benefits.

The Devil’s Slide Tunnels were a test case for the North American market, which has since embraced the use of macro synthetic fibres in all types of civil tunnelling applications.

  • Devil’s Slide Tunnel
  • Devil’s Slide Tunnel
  • Devil’s Slide Tunnel
  • Devil’s Slide Tunnel

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