Work on drainage tunnel project inaugurated

Al Mawlawi was accompanied by Guido De Sanctis, Italian Ambassador, and senior officials from Ashghal, including Jalal Yousef Salhi, Director, Infrastructure Affairs, and Hamad Mohamed Al Tamimi, Director, Asset Affairs.

Also present were representatives from Ashghal's Roads and Drainage Operations and Maintenance Department, CDM Smith, Project Consultant, Salini Impregilo Construction Company, project contractors, and Herrenkenecht, German manufacturer of tunnel boring machines (TBMs) being used to excavate tunnels.

Excavation is being carried out by Al Thummama, one of the two technologically advanced TBMs being used for the first time in Qatar and specially designed and developed for the project.

The Mesaimeer tunnel for surface and ground water is one of the key drainage projects within Ashghal's plans to upgrade Qatar's drainage network.

The tunnel will run under F-Ring Road, stretching 9.7km. It will run 5.4km from Al Thummama to the west and 4.3km to the east to the planned pumping station near new Hamad International Airport.

The tunnel will alleviate Doha's storm water by transporting it from a 170 sq km of catchment area, covering southern and western parts of greater Doha.

It will be linked to existing and planned drainage network in the areas it will traverse.

To allow access for inspections and regular maintenance of the tunnel, an operations and maintenance plan has been developed to ensure satisfactory operation of all elements. This will be facilitated through 21 access shafts linking ground level to 20m-30m depth of the tunnel.

Named after the areas where the TBMs will operate, and measuring 4.5m diameter and 121m long (including support equipment), 'Al Thummama' and 'Al Rawada' possess a significant capacity to excavate tunnels without causing any adverse effect on surrounding structures and disruption to traffic.

The specially manufactured TBMs operating through pressure balanced excavation technology are ideal for Doha ground conditions at a depth of 30 metres. This technology will facilitate the construction of essential infrastructure tunnelling which is paramount to accomplish a sophisticated tunnel network.

Over the past 16 months, Ashghal has been involved in rigorous planning and preparation process for the tunnelling project. The works included design, fabrication and installation of TBMs, geotechnical investigations and site mobilisation. Excavation works were conducted to prepare the launching tunnel and additional elements to support the TBMs such as portal cranes and other enabling requirements were installed.

The project is scheduled to be completed by early 2017.