Construction Week reported that Italian construction firm Impregilo has won a contract to build the first 15 kilometers of a hydraulic tunnel in Abu Dhabi.

The deal, worth USD 243 million will see Impregilo start work on the tender from the Abu Dhabi Sewerage Services Company at the end of the year.

The project, named the Strategic Tunnel Enhancement Program will see the company build a tunnel with an excavated diameter of 6.3 meters and 6 access shafts to depths of between 40 meters and 50 meters. The tunnel will form part of a larger 40 kilometers gravity tunnel to collect waste water on Abu Dhabi Island and mainland and convey it to the treatment plant in Al Wathba.

Impregilo said in a statement that “Technically and organizationally, STEP is a particularly complex project. It will involve simultaneous use of three earth pressure balance tunnel boring machines, to excavate and at the same time case the tunnel with precast concrete sections. This is the first time this advanced mechanized excavation technology has been used in Abu Dhabi.”

The hydraulic tunnel and the access shafts will be lined with a special membrane to keep the concrete sections fully protected against the aggressive environment, for a minimum duration of 100 years.

(Sourced from Constructionweekonline.com)