Towers and tunnels
Superlatives soon run out when you try to describe the development that is going on in Dubai, where every building or development seems to set a record. Middle East Foundations Group is the company that prevents these remarkable buildings from sinking into the sand and its acting managing director Jose Thomas explained how to John OÔÇÖHanlon.
Fuelled by oil, Dubai is famous for ploughing its wealth into projects that will keep it going once that oil has dried up. It aspires to be a centre for tourism, to attract wealthy residents and whole industries (notably media and IT) and along the way be a showcase for the finest and most dramatic buildings in the world.
ThereÔÇÖs much in favour of this strategy, but quite a few things against it, one of which is the fact that Dubai is set in quite unforgiving surroundings, with sand very much in evidence in the landscape and underfoot. Not that Dubai is scared of taking on this environmentÔÇöit has reclaimed land for the extraordinary ÔÇÿpalmÔÇÖ islands that have become some of the hottest real estate on the planet, and it is creating a skyline to eclipse any in America. The Dubai Metro, started in 2005, will be the worldÔÇÖs longest driver-less automated mass transit system, and a first for the Middle East.
All this construction takes place on a less than ideal platform. Several metres of sand cover bedrock of sandstone that gets increasingly strong with depth, but itÔÇÖs never going to be granite. Nevertheless, it supports some remarkable skyscrapers, including the $4.1 billion Burj Dubai, the tallest structure on the planet. Burj Dubai is almost complete, and near it in the Business Bay area of the city, Burj Al Alam will soon be rising to become the tallest purely commercial building in this city of giants.
The architects of these massive buildings and infrastructure projects get plenty of media attention, but one hears less often about arguably the most important contributor of all. Any building is only as good as its foundations, and before a single pillar or floor rises above the surface, adequate footings need to be in place to support the structure. What links the metro, the reclaimed islands and the skyscrapers? It is the prosaically-named Middle East Foundations Group (MEFG), a company established in 1995 by its chairman Aidroos Hassan, and one that has since grown into the leading foundation contractor of the UAE. It provides a range of geotechnical services including pile foundations, barrette foundations, temporary ground improvement techniques, diaphragm walls, secant walls, permanent and temporary ground anchors, grouting and steel sheet piling.
ÔÇ£Our extensive experience and engineering capabilities in the field of foundation engineering as well as post tensioning works has enabled us to deliver a unique system of post tensioned diaphragm walls,ÔÇØ explains acting managing director, Jose Thomas. ÔÇ£We have implemented this system in a number of projects in Dubai, giving clients cost effective and efficient solutions in response to challenging requirements.ÔÇØ
If you visit the site of Burj Al Alam today you wonÔÇÖt see much above ground, but the foundations are being laid at a steady pace, with a large amount of piling work currently in progress. MEFG was awarded the shoring and piling contract for the $1 billion project, says Thomas, even before the building contracts had been finalised. ÔÇ£There is no main contractor on board yet, but we are working with the consulting engineer to get the initial phase finished. Excavation is already complete and we are installing large diameter bored piles.ÔÇØ More than 146 of the 613 piles required for the foundations of the pioneering project have already been installed; the piling work should be completed by January 2010 and the developer, Fortune Group, is confident that it will be able to meet its 2012 completion deadline.
MEFG has 80 people working on this project site, says Thomas, and has deployed its high torque drilling rigs to install the concrete piles that are normally used in this terrain. ÔÇ£Driving steel piles is rarely an option in an increasingly built-up area because it would have too much impact on nearby structures and would also not be a feasible solution in these kind of subsoil conditions,ÔÇØ he explains. The piling work on this job alone will consume more than 58,000 cubic metres of concrete and 5,000 tonnes of steel, and 180,000 man hours will be required to complete it. Then comes the easy partÔÇöerecting the building!
Though Burj Al Alam will be the worldÔÇÖs tallest office block at 1,673 feet high, it is dwarfed by the mixed commercial and residential Burj Dubai at 2,684 feet. MEFG was the lead contractor for the foundations for that too. ÔÇ£Burj Dubai required very sophisticated foundations, using 45,000 cubic metres of concrete,ÔÇØ explains Thomas. ÔÇ£The tower stands on 192 piles, each 164 feet deep. Large boreholes were filled with viscous polymer slurry that is denser than water but lighter than concrete; when it is poured into the hole, the concrete displaces the slurry and hardens to form a foundation pile.ÔÇØ Thomas himself undertook the role of project director on this job. ÔÇ£Installing the foundations for Burj Dubai was very challenging, but the ultimate experience,ÔÇØ he recalls.
Laying the foundations for the metro system was a little different but no less sophisticated and challenging. Massive piles up to diameters of 2.8 metres were needed to support the track where it follows the course of existing roads. For the stations, MEFG also installed the diaphragm walls to act as a water and earth retention system which then became a permanent part of the structure. The average depth of the underground stations is 26 metres, Thomas says, but these walls go down 57 metres and where the tunnel-boring machines penetrate the diaphragm walls, special engineering techniques (tunnel soft-eye) are employed to facilitate this.
The list of MEFGÔÇÖs projects is endless. It also installed the foundations system of the Dubai MallÔÇöunsurprisingly, the worldÔÇÖs largest. Perhaps the companyÔÇÖs greatest asset (after its people, of course) is its track record, which is what gives clients the confidence to keep coming back; and this mass of references will win it contracts in other markets. Though most of its work to date has been done in its own backyard, it is time the company took its place on the global stage, says Thomas. ÔÇ£We have our eyes on the Singapore Metro, for example, and a number of infrastructure projects in Iraq. We have always provided our clients with the best resources employing the best known techniques and machineries for each project. However, the prime asset that drives Middle East Foundations Group remains the team of highly experienced and dedicated specialist engineers and professionals from all around the world, including Europe, Singapore and Malaysia.ÔÇØ
Until lately, there was more than enough local work to keep MEFG stretched; now that the recession has slowed investment, the time is right to look further afield, Thomas says. ÔÇ£We are much more than just a foundation specialistÔÇöwe have a post tensioning division now and have provided that service on 200 bridge contracts over the last three years. We also have a ready-mixed concrete division and a de-watering division for foundation work. We are a much more diversified company, and are really confident that we can sell these services in other markets.ÔÇØ
