Role for Leister in Constructing Tunisia's First Road Tunnel

Success Stories9 Feb 2018

Tunisia is Africa's northernmost country, with a coastline along the Mediterranean Sea to the north and east, and two bordering countries: Algeria to the west and Libya to the south-east. Spanning some 163’610 km2 / 63’170.2 mi2, it is approximately twice the size of Austria. Tunisia boasts a highly competitive economy and a population in excess of ten million.

Author: Silke Landtwing, Manager Corporate Communications, Leister Switzerland

First Road Tunnel Project – Sealed Using Geo-Synthetics

In an effort to stimulate its economic and social development, the Republic of Tunisia is making investments in its road infrastructure. For the first time in the country's history, this is involving the construction of a road tunnel featuring state-of-the-art sealing work that uses geosynthetics.

Over a total length of 3 km / 1.86 mi, the intention is to link the GP10 and X thoroughfares in the Tunis and Ariana regions by means of four tunnels – with four lanes. The tunnels in this case are covered trenches whose length stretches over 1.2 km / 0.75 mi in total. Construction is scheduled to be completed within 30 months.

PERLA Group Engages Leister for Tunnelling Work

The PERLA Group is Tunisia's leading company in the field of sealing work and new solutions for property and infrastructure projects. Anis Samara, Technical Director and partner in the PERLA Group, knows that it can rely on Leister: „PERLA is executing the sealing work for all four tunnels simultaneously. To ensure that a high standard of quality is maintained consistently, we are using Leister automatic machines and tools for welding and sealing the PVC membranes.“

TWINNY T – TWINNY S and TRIAC ST Playing a Role

PERLA teams are using the TWINNY T and TWINNY S automatic welders, plus TRIAC ST tools, to weld 30’000 m2 / 322’917.3 ft2 in total of translucent PVC membranes measuring 2 mm / 78.7 mil thick, as well as 1.9 mm / 74.8 mil protective membranes. To seal the tunnel walls, the Leister automatic welders and hand tools will be used in both vertical and horizontal positions.

TWINNY T – For Welding Any Kind of Tunnel

Leister automatic welders ensure that stability remains constant and parameters are consistently monitored during the welding process. For that reason, PERLA has opted for Leister's TWINNY T automatic welder to carry out its tunnelling projects – a sound choice, as the TWINNY T has already proven itself in dozens of tunnels the world over. The most famous application in which it has been used is Switzerland's Gotthard Tunnel, which is more than 50 km / 31 mi long and opened to rail transport in 2016.

The TWINNY T is fully controlled and ensures that both temperature and welding speed remain stable under changing site conditions. In Tunisia, these come in the form of significant temperature fluctuations: The country experiences heat of up to 40°C / 104°F in summer, but a somewhat frosty average of 0°C / 32°F in winter.

Testing Leak-Tightness With Compressed Air


Leak-tightness is being tested using compressed air testing equipment in the inspection duct between the two edges of the welding seam.

Tunisia – A Leading Light in Africa

With the high standards of construction it delivers in its infrastructure projects, Tunisia is setting the bar high – so there is little question why it has become one of the African nations' leading lights.

Leister is proud to play a role in implementing these infrastructure projects.

Leister Sales Manager Africa Rachid Benlakhouy is your contact for further information.