Site visit: Damac Heights
The 86-storey tower being built on a high-profile Dubai Marina plot
“I’m very excited,” Samer Skaik, senior projects manager at Damac Heights explains when he’s asked about how he feels being in charge of such a high-profile project.
“It is like your baby. You see it growing every day. When 2016 comes (the building’s completion date), I will tell my kids, this is your brother.”
Skaik, a Palestinian, is visibly enthusiastic about the project during his interview with Construction Week, and it is easy to see why. After all, there aren’t going to be many more super high-rise towers built overlooking the Arabian Gulf from Dubai Marina – simply because the plots are no longer available.
“You will not build such towers every day – maybe once or twice in your life,” he says.
This tower sits on a prominent site between the Dubai Marriott Harbour Hotel and the distinctive twisting tower, formerly known as Infinity Tower but renamed as Cayan Tower by its Saudi developer on completion last year.
It has an intriguing design of its own, which was created by architects Aedas. The building curves from its base to tip, meaning there are no regular floorplates.
“When we started working on the concept design, there was a target that we wanted something different,” says Skaik. “We wanted to go away from typical floor schemes, so we tried to start with something that is tilting in two directions.”
This presents its own sets of difficulties in terms of construction, but these are not the only challenges it faces.
The first relates to its location. Overlooking the Arabian Gulf to the front and Dubai Marina immediately behind it means the building offers spectacular views, but it also means the water pressure on both sides of the site is high, especially as it has been excavated by 24m in order to fit in five basement floors.
“Whenever you are doing business in the Marina, it is very challenging. You have water from both sides – the ocean and the Marina itself.
“That’s why we took intensive care when we did the design and construction of the shoring system. You need to make sure you are independent in terms of water ingress.”
Digging down so deep on a site can present unforeseen issues, such as fissures, cracks and cavities in the ground. Skaik says that the shoring system created therefore needs to make sure that it is impermeable to any water leakage.
The shoring system used was a mix of secant piles and diaphragm walls, which Skaik says was the most reliable and water-tight method for such a deep excavation.
Ground anchors could not be used for the shoring walls at the marina side due to the proximity of the Marina’s lake as well as the huge water pressure behind the front and rear walls.
Therefore, temporary contiguous piles were built against the unanchored shoring walls and the sand filling in between was structurally sufficient to support them.
This meant the substructure had to be built in two phases. Slabs built in the first phase were used as a support for internal struts, which were then inserted at various levels as a replacement for contiguous piles.
The piles were then cut gradually and the filling sand removed as struts were put into place. Eventually, the struts are removed as the substructure is completed, with the slab edges then providing the necessary shoring.
The piling and shoring work was carried out by Turkish contractor Zetas shortly after contracts for the tower were awarded in the third quarter of 2011.
It took around six months to complete before main contractor Arabtec moved onto the site for substructure works in the first quarter of 2012.
Structural and MEP design, safety procedures and project management support for the tower have been put in place by Aecom, while Damac’s own in-house project management team is overseeing the work.
Interior designs for the health club, common areas and the first 43 floors are also being carried out by the developer, but the top 40 floors in the building represents one of the first two projects which have been a collaboration between Damac and designer brand Fendi.
Its interior design arm, Fendi Casa, has created the fit-outs for the top 40 floors in the building, which has been branded Damac Residenze.
The tower contains 600 apartments, a temperature-controlled swimming pool, gymnasium, nursery, a steam room, spa facilities, a cinema and a kids play area.
It also has 12 lifts. Five of these will serve a low-rise zone, three mid-rise, three high-rise and there is one service lift.
Its positioning, at a busy intersection of Al Sufouh Road at the entrance to the Marina, and the general lack of parking space nearby, means that 10 floors of parking has been created within the building to meet municipality requirements – five of these are at basement level, with another five on the podium. The swimming pool and health club sits at the top level of the podium.
“When you have 10 floors with five basements you have to create ventilation systems, you have to know how to evacuate people in case of incidents.... It is a special building,” he says.
The site’s location also made the pour for the building’s huge raft something of a logistical challenge.
The pour, which took place during the second quarter of 2013, involved a continuous 70-hour stint with four pumps pouring at between 30-40m3 per hour. In total, some 8,600m3 of concrete was pumped over 1,070 tons of steel.
Skaik says that a lot of consultation needed to be done both with Dubai Municipality and the Roads and Transport Authority to co-ordinate the work, which began at the weekend when traffic in the area was lighter.
“We had about 55 flagmen on the streets to make sure traffic was not affected because we had so many mixers coming backwards and forwards,” he says. “It was very challenging for everyone involved – the labourers, the supervisors and the project managers to make sure that this will happen as per our schedule.”
Following this, work started on the ground floor, which Skaik said is complex as it houses substations and a lot of the building’s MEP systems. The slab is also thicker, and there are atypical areas such as the building’s lobby and space for a ground floor restaurant.
The podium’s structure has also completed and Skaik says that the cycle for construction of each of the slabs has become quicker as work has progressed onto the apartment floors.
Casting for the seventh floor was due to take place when Construction Week visited the site in late March, and the ninth floor was being cast last week.
“Now we are speeding up the whole process,” he says. “The programme calls for seven days, but we are trying to finish the cycle within five.
“We want to have a buffer for future incidents or for something you may not forecast such as a shortage of materials.”
On lower levels each floor contains ten apartments but as the building curves towards a point at the top floorplates become smaller, so the number of apartments is reduced.
There are also three double-height mechanical floors installed on upper levels after every 20 floors.
“I have done some jobs in a 3.8-day cycle because they were typical floors, but you cannot do that here.”
Arabtec is using post-tensioned slabs, with CCL as the post-tensioning contractor, which Skaik says helps to keep slab cycle times down. A slip forming system is also being used for the building’s core, which is generally running around three levels ahead of the slabs.
“Every floor is different as the building is tilting. The challenge is to make sure the slab edges are co-ordinated in an appropriate manner. You have a surveyor who is qualified to locate the columns, the edges of the slab and the locations of items for the curtain wall to go up later on.”
There are currently around 600 workers on site and more than 1.3mn hours has been completed without any serious incidents. The number of workers is scheduled to peak at around 3,000 when all areas of the project are open, which is anticipated to be in August next year. The structure is expected to top out shortly after this, and the building is due to complete in mid-2016.
“We are trying to do it earlier. The contractor has a plan to mitigate and see if he can do it ahead of programme, because he wants to release his manpower for other projects.”
Skaik says the fact that work started on this project in 2011 when work was quieter has meant that it has benefitted from “having a very good team”.
“I started learning when we were still in the piling stage. So imagine the knowledge you are earning when you do this.
“It is very special and we are using lots of different technologies.”
For him, it is his second tower project, having previously completed Damac’s Park Towers in DIFC. He also worked on the creation of Dubai’s Za’abeel Park.
“I feel that I am lucky. I have done parks, mixed-rise buildings, villas, high-rise buildings and then hotels. Now I am doing a super high-rise building.”