Support Systems

Temporary Support Systems

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Temporary support is defined as any system designed and installed to support the perimeter of an underground opening between the time it is first excavated up to the time that a permanent lining is in place.

We can divide these supports into 4 main categories:

- Support acting by applying a confining pressure to the surrounding ground

 
  • shotcrete

 
  • shotcrete with lattice girders

- Support applying both a confining pressure and acting as reinforcement of the surrounding ground.

This type of support includes various types of rock bolts such as :

 
  • ungrouted mechanically or chemically anchored rock bolts

 
  • grouted (resin or mortar) rock bolts

 
  • driven anchor bars

- Systems providing plain "brute strength support

 
  • heavy steel ribs

 
  • lattice girders

 
  • steel linings

 
  • concrete segments

 
  • driven tubes (umbrella arch)

 
  • shields

- Systems which consolidate the ground to amend its geotechnical and/or hydrological properties.

 
  • consolidation grouting

 
  • compressed air

 
  • freezing

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To know more

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External Links

Recommendation on " Choice of tunnel support" AFTES WG7

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