Pooling resources keeps ACC on track
The extension to the Meridien Mina Seyahi hotel is now just six months away from completion. Christopher Sell talks to main contractor ACC to understand how the firm utilised its massive Dubai workforce to keep the project on time.
Satisfying Dubai's thirst for tourism is an ongoing challenge, with hotel companies continually looking to attract those who arrive in the emirate in ever increasing numbers. The number of visitors to the Gulf is set to reach 15 million by 2012, and more hotels than ever are needed if the city is to meet demand.
Located in Dubai Marina, the US $95 million (AED350 million) Le Meridien Mina Seyahi extension is in the final stages of construction, and is a perfect demonstration that classically designed buildings, which incorporate ornate and sophisticated design, can still be achieved in the region and do not necessarily have to pose greater construction challenges.
Designed by consultant Arch Group and being constructed by ACC, the new five-star hotel is scheduled for completion in August 2007, and could be opening its doors one month later. Work on the main structure has been completed, while cladding, finishing work and landscaping is underway. A service tunnel linking the two hotels has also been mooted, but at this stage it is unclear when this will be built.
Unlike tower structures, the advantage of such a design is that the site can accommodate a far larger workforce at the early stage of construction than would be possible on a standard tower.
"Although this does mean that greater supervision is required to oversee such an inflated workforce over a site of this size," says Emad Bordkani, project manager, ACC.
"It's not a vertical construction, it is horizontal, which is good, as you can deploy more people if you fall behind schedule. Whereas with tower construction you have to wait in sequence - you cannot do the 14th floor until you have finished the 13th - for example," he adds.
Bordkani also explains that such a structure is also advantageous during construction when it comes to creating more space for work and installing lifts.
"When you finish the first floor, for example, you have all the area available to do your finishing work, plastering, ceilings and so on. And with a tower you cannot install lifts until you finish the core. Whereas with this type of design they can be installed from the 3rd floor." When complete, the building will have 21 lifts.
While it doesn't represent the same challenges inherent in tower construction, the 300-room hotel still raises some unconventional issues that have to be overcome; specifically due to the sheer size - the project occupies a 200m by 120m area with a total built up area of 80,500m2 - more machinery is required on site than normal.
Bordkani explains that due to the elongated nature of the hotel, an unusual number of cranes were required during construction, which had to be closely monitored at all times. "The complicated thing was the tower cranes. We had six on site, and had to be careful and coordinate to ensure the booms did not clash," he says.
Each of the cranes had a boom length of between 50m and 60m, meaning there was insufficient space for each crane to swing around at the same level, so all their booms had to be at different heights. Coordination with the banksman on the ground therefore was essential as the crane operators' vision was limited.
For 10 months the site was operating with six cranes, which have now been reduced to three. Twenty-five contractors and subcontractors currently operate on the site, which hosts up to 1,200 labourers, another by-product of the site's shape and size.
Other factors have also influenced the construction schedule. ACC was forced to delay the construction of the site following last minute changes to the design. According to Bordkani, a number of rooms were discovered to have restricted sea views due to the wings of the hotel protruding too far. "We had to stop work for a re-design and a building permit, which meant we stopped totally for 75 days," he says.
Bordkani adds that while construction did not take place, mobilisation and preparation work was carried out as much as possible to avoid standing idle. The modified design saw the wings at either end of the hotel reduced by half and the resulting shortfall in rooms was compensated through an additional storey being added, bringing the hotel to nine stories and 46m in height.
Despite its proximity to the sea, the hotel is not encumbered by a high water table, says Bordkani, and as such was not presented with any de-watering or piling challenges in the early stages of the build. The water table was measured at -7m, while the building platform is at +1m.
Typically, the local suppliers market did cause some logistical headaches, with the lack of skilled labourers being a problem on a site such as this, which requires finishing work of a high calibre. "Here we have a problem with small nominated contractors and subcontractors. When we are facing a shortage they are not available in this market because it is booming. You cannot easily find contractors, and if you require specialists such as a plasterer, they are not available or their rates are very high."
To overcome this ACC was forced to stretch its resources and procure staff from other projects where necessary. For example, if one site was using 50 masons, they would take 25 to make up the shortfall. This can have the added advantage, says Bordkani, of not just bringing site schedules up to speed but reducing idle time among workers.
The concrete work of the build comprises columns, beams and precast hollow-core slabs, the design of which was changed during the value-engineering stage of the project. The slab initially specified by the Arch Group was thicker than what ACC offered. The new material, measuring 60cm rather than 80cm meant less weight and reduced costs. An added advantage of precast over cast in situ was that a contractor can go for more span with precast - up to 10m - rather than in situ, which is limited to 6m. Around 55,000m2 of hollow-core slabs will be used when the hotel is completed. Concrete was supplied by Abu-Dhabi based Transgulf.
The total concrete pour is 25,000m2 for the project's beams, columns and foundations. The grade of concrete used is 40, 50 and 60. For the columns up to the third floor it will be grade 60, reducing to 50 and then 40 as the structure ascends.
Bearing more than a passing resemblance to the Emirates Palace Hotel, the Le Meridien Mina Seyahi extension represents a more classically-designed hotel and will perhaps inspire other developers to see that hotels can be aesthetically pleasing and architecturally robust without necessarily resorting to the staid, modern high-rise that can commonly be seen along the emirate's coast.