From Cairo’s metro to Abu Dhabi’s super-sized 40-km sewer, tunnelling is enjoying a busy time in a relatively new market. The Middle East and Africa are giving the international tunnelling community a lot to be optimistic about, particularly the Gulf States such as the UAE, Qatar, Saudi Arabia and Kuwait. “Twenty to thirty years ago it was impossible to think that Gulf States would ever embark upon tunneling or metro schemes but under the new 2030 development plans, regional governments are reclaiming the city and utilising the third dimension,” says Martin Knights, immediate past-president of the International Tunnelling Association.
The most significant development in the Gulf’s tunnelling sector to date has been the USD-7.6bn Dubai metro project, which has almost doubled in price from the original USD-4.5bn budget. The first 52km Red Line opened on time in September 2009 and the second, 23-km Green Line opening date has been extended from March 2011 to August 2011. A total of 7.9km of this section is underground including six stations.
The contractor consortium is led by Japan’s Obayashi Corporation, with Kajima Corporation, Mitsubishi Heavy Industries and Turkey’s Yapi Merkezi.
Despite the cost and time overruns the project remains a major achievement for a region with no previous experience of TBMs or light rail. Of the first 70km of light rail system, 13km were tunnelled using three 9.56m-diameter Mitsubishi EPB GBMs in 10 separate drives.
Plans for extensions of the metro are currently on hold as Dubai weathers the financial storm battering its state owned development companies and affecting governmental infrastructure spending. However Knights expects Dubai’s metro will be extended in the future. Other states, he says, are also pursuing tunnels for metros, utilities and road links. “In the future I believe we are going to see the use of strategic tunnels linking islands in the region, instead of bridges and causeways.”
Most current tunnelling activity is centred on Abu Dhabi, which along with plans for its own light rail system, is also building a new sewer network. Known as the ‘strategic tunnel enhancement programme’ (STEP), it is designed to replace the existing pumped wastewater network with a new gravity sewer system. A total of six contracts are being awarded including three for the main 40km sewer, two for the connection pipework and one for a new pumping station. The main bore will run from Abu Dhabi Island in the north down to the new Al Wathba sewage treatment works on the mainland in the south. The first two contracts for this were awarded to Italy’s Impregilo. The first was awarded in the summer of 2009 and concerns a 15km long section with a 5m internal diameter that makes up the central piece of the sewer. Another contract for the final 10km length of sewer with a 5.5m internal diameter was awarded at the end of November.
A total of eight EPB TBMs will be used on the bore. The three 5m diameter, three 6m diameter and two 6.5m diameter machines are set to remove 1.2 million cubic metres of fill. Contractors are expected to bore through the sandstone, mudstone and gypsum at rates of 100m per week. Korea’s Samsung is understood to be among the bidders.
Contractors tunnelling in Abu Dhabi will need to carry out extensive ground investigation as the area is prone to large sub-surface voids. “Regional geological formations lend themselves to karstic formations. These can be discrete or sometimes widely connected. You have to carry out very, very good site investigation,” says Knights. “And be mindful of your pump rates when grouting.”
It is not just Knights who is confident of the region’s potential for tunnelling. On 22 February 2010 Germany’s Herrenknecht signed an USD-8.7M agreement to establish a joint-venture TBM manufacturing company with Abu Dhabi’s Aabar Investments. “The business objective is the continuous market development of mechanised tunnelling in the MENA region (Middle East and Northern Africa),” said a Herrenknecht spokesperson.
The German giant is already supplying a TBM to Qatar, which is increasing stormwater storage in the Qatar capital of Doha, and in Saudi Arabia it is supplying drilling equipment to Saudi Aramco for a new 3-km oil pipeline.
Along with its stormwater storage plans Qatar is also set to move ahead with a 340-km metro system, which is expected to involve a significant portion of underground construction, and a 10-km road crossing under Doha Bay. The 2 December announcement that Qatar had won a bid to host the World Cup in 2022 will give the projects a significant boost as the bid documents outlined the metro as the main mode of transport for visiting football fans. Stations will be located at the major stadia such as the planned 86 000 capacity Lusail Stadium and the first 30-km ‘Red’ line will run north south through the city linking New Doha International Airport with the Lusail development. The project is being managed by a joint venture of Qatari Diar Real Estate Investment Company (QDREIC) with DB International, the international consulting arm of Germany’s Deutche Bahn. According to the bid documents the network will be 70 per cent complete by 2020, serving all stadia.
Throughout the region there is no shortage of planned schemes. Damascus (Syria), Amman (Jordan), Kuwait City, Baghdad (Iraq) and Tehran (Iran) and Riyadh (Saudi Arabia) are all planning metros and are keen to learn from pioneering Dubai’s experiences. Further afield in North Africa, Egypt is extending its metro by adding a third line. A Vinci Construction Grand Projects-led consortia is undertaking a 3.5km, 9.5 diameter bore under the River Nile. Construction is scheduled for completion in mid 2011.
With so many projects planned and several underway it is no wonder that the industry is excited about the regional opportunity.
