The Highway 1 Expansion Project includes the excavation of a dual tunnel below the HarEl Interschange. The tunnel is comprised of three lanes in each direction and a service (utility) tunnel.
The tunnels’ excavation includes a lining system by means of P.V.C films and above them a concrete casting (lining). It was impossible to cast the concrete while using molds in the service (utility) tunnel due to the tunnel’s varying cross-section.
It was decided to carry out the lining using Sikaplan films and directly spraying concrete onto the Geomembranes. The sprayed concrete will serve as the final layer of the service (utility) tunnel.
Excavation, preliminary bracing and concrete spraying – base layer.
Installation of 2 mm thick Sikaplan P.V.C films, including a protective geotextile.
Installation of an ø8@10X11 iron Geonet using anchoring stakes atop the Geomembranes
Spraying an initial concrete layer (5 cm).
Installation and anchoring of a second Geonet.
An additional concrete spraying (15 cm).
Spraying a last concrete layer (5 cm) mixed with polypropylene fibers (supplied by Admir Technologies).
Installation of an effective lining system between the concrete sprayed layers in the tunnel without the need for casting with a mold. This solution allows the execution of lining works using P.V.C films within niches and small spaces as well as additional lining in existing tunnels in which a leak is located.