High-Strength Expanded Polystyrene

HS-EPS Tunnel Elements

Challenging ground conditions in tunnelling projects are mastered with HS-EPS (High-Strength Expanded Polystyrene) tunnel elements: a safe, lightweight, and flexible solution that revolutionises how to handle squeezing ground in tunnel construction.

Installation of the novel HS-EPS yielding elements in geotechnical challenging conditions

The HS-EPS solution in a nutshell

The novel yielding element is the key to your successful tunnelling in geological complex and challenging conditions. Implenia's geotechnical experts support clients, structural engineers, and contractors in all project phases - from pre-design, tender design, and detailed design to technical installation of HS-EPS tunnel elements on-site in the tunnel.

Key benefits

HS-EPS yielding elements are novel supports for ductile shotcrete linings in squeezing ground conditions. They convince with their favourable properties and easy installation. 

Weight Flexibility Durability Other
The newly developed HS-EPS yielding element weighs just under 20 kg and can thus be installed by one person
The newly developed HS-EPS yielding element weighs just under 20 kg and can thus be installed by one person

Weight

Lightweight product in comparison to current market solutions, enabling faster installation under better conditions in terms of safety and ergonomics for your workers

  • Faster and easy installation in a time-critical process in about 5-10 minutes per element, with just one person
  • Weight savings of approximately 70 % (10-20 kg vs. 60-80 kg)
  • Avoidance of incidents and hazardous situations during overhead installation
HS-EPS tunnel elements act as compressible structures in a segmented shotcrete lining when subjected to external squeezing conditions
HS-EPS tunnel elements act as compressible structures in a segmented shotcrete lining when subjected to external squeezing conditions

Flexibility

Flexible concept, enabled by a layered “sandwich” system, allowing for tailored and adequate response to various geological conditions and construction methods

  • Customisable stress-strain behaviour
  • Flexible sizing on-site
  • Variable heights

 

Testing HS-EPS tunnel elements
Testing HS-EPS tunnel elements

Durability

Durable closed-cell structured material with inherent hydrophobic characteristic, resistant against moisture and suitable in groundwater.

  • Non-corrosive
  • Chemically resistant in tunnel environment

Other benefits

  • Cuboid shape prevents tilting of the elements in case of anisotropic displacements
  • Layered approach allows for last minute adjustments in the tunnel construction process
  • Short lead time for production
  • Flexibility allows the elements to be used on next construction sites

When you reach technical limits, innovative solutions must be developed, which we successfully did here at the Semmering Base Tunnel. 

Manuel Entfellner
Implenia Austria GmbH

HS-EPS tunnel elements revolutionizes the way to respond to squeezing ground in tunnel construction

The lightweight of the HS-EPS material compared to conventional products significantly reduces the installation process, which directly impacts the cost and time. Furthermore, flexible, project-specific adjustment of the stress–strain behaviour due to the variable configuration of the panels (sandwich construction) is a significant advantage. The size of the elements can also be adjusted to varying needs. The HS-EPS yielding elements allow full-surface transmission of the tangential forces into the shotcrete lining, thus providing resistance against tilting in the case of high differential deformations.

Would you like more information?

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Watch the video!

After more than two years of testing, laboratory- and field experiments, the HS-EPS tunnel elements are ready for large-scale application.

Strongly based on both, scientific geotechnical expertise and many years of tunnelling experience, our solution is now ready to be installed in other challenging tunnel projects worldwide.

With the new HS-EPS yielding elements and our in-depth expertise, we could tunnel through difficult geological-geotechnical fault zones with deformations up to 100 cm.

Helmut Wannenmacher
Implenia Austria GmbH

Reference

Client: Austrian Federal Railways (ÖBB). Contractor: Implenia Österreich GmbH, Hochtief Infrastructure GmbH and Thyssen Schachtbau GmbH.
Client: Austrian Federal Railways (ÖBB). Contractor: Implenia Österreich GmbH, Hochtief Infrastructure GmbH and Thyssen Schachtbau GmbH.

Semmering Base Tunnel, Lot SBT 1.1

The approximately 27.3 km long Semmering Base Tunnel is one of the most important and complex infrastructure project in the heart of Europe. This double-tube railway tunnel is located between Gloggnitz and Mürzzuschlag, linking the two federal states of Lower Austria and Styria.

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Implenia's contact for HS-EPS Tunnel Elements

Manuel Entfellner
Geotechnical Engineer
+43 664-881 87 738 manuel.entfellner@implenia.com Linkedin Download VCF-Card Business card
Helmut Wannenmacher
Technical advice and sales
+43 66 488 18 77 00 helmut.wannenmacher@implenia.com Linkedin Download VCF-Card Business card

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HS-EPS Tunnel Elements

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KEYWORDS

  • Yielding element, yielding layer, yielding support, Stauchelement
  • Squeezing ground, squeezing rock, druckhaftes Gebirge
  • Tunneling, Tunnelbau
  • Yielding zone, deformation zone, Knautschzone
  • Ductile lining, deformable lining, nachgiebiger Ausbau
  • Yielding principle, Ausweichprinzip

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