Case Study: 007
Tunnel Lining
The Task
Our customer has constructed a MATIERE Pre-cast Arch System to form a
cut and cover tunnel, allowing passage of a commercial rail line with
the construction of a dual carriageway above. The outer surface of the
interlocking pre-cast tunnel sections required a waterproof
geomembrane barrier for which F.L.I. Environmental was awarded the
contact.
The Solution
F.L.I. Environmental proposed the use of 2mm thick HDPE (High Density
Polyethylene) lining, which was placed in panels across the
circumference of the tunnel. At the leading edge of each open end of
the tunnel liner was continuously fixed to the structure using a
stainless steel batten, bolted into the concrete. A neoprene gasket
strip was used beneath the liner to ensure a watertight joint.
Individual liner panels were joined by fusion welding and each fusion
seam was subsequently non-destructively tested by air pressure.
To prevent the build up of water at the cover soil / liner interface,
a geocomposite drainage material was installed over the liner
providing a preferential water flow path to collection drains at the
tunnel base. |
Matiere Pre-cast Arch Installed
Waterproofing HDPE Liner Installed
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General
F.L.I. Environmental has experience in both exterior and interior
tunnel lining and is well placed to provide advice in the selection
and technical installation of suitable geosynthetic products for these
applications.
Project
Drogheda Bypass, Dublin
Main Contractor
Siac O'Rourke (JV), (ABM Construction - Tunnel Contractor)
Consultants
Roughan O'Donovan
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