Sector 6 of the Jumeirah Beach Residence (JBR) project is different to other contracts on the project in that it features a massive 16,000 sq m podium area over the complete project site, rather than individual podium levels for each tower.

In winning Sector 6 of the JBR project in Jumeirah, Dubai, main contractor Al Shafar General Contracting Company has purpose-ordered a variety of new equipment to meet the tight contract period of the 16,000 sq m, four-storey-high podium. The list includes: new formwork systems from Doka, new passenger/material hoists from Alimak and Liebherr luffing jibs 112HC-L cranes (JBR is only the second project in the region to use the cranes).
Jumeirah Beach Residence – covering an area of 4.5 sq km on the shore side of the Dubai Marina and featuring a 3.5 km long man-made lagoon  – includes a total of seven construction packages to provide 36 residential high-rise towers, four hotels and beach clubs to cater for a community of 25,000 people.
The Sector 6 contract features four high-rise towers with varying heights between 107 m and 172 m plus a 120-m-high building linking two of the towers.
The podium level is different to the other sectors in that it is a ‘stand alone’ podium and will be connected by a series of bridges to the other podiums.
Al Shafar kicked off work on the Sector 6 in March last year with concrete pours for the raft foundation.
Says project manager, Ehab Edward Narouze: “The depth of the raft for the tower ‘foot print’ is approximately 2.8 m and 1.4 m for the general raft across the remainder of the site. For each tower’s raft, approximately 5,000 cu m of concrete was poured.”
Once the raft was complete, the contractor – using a Doka Top50 climbing formwork system – started work on the tower’s core shafts, working two levels ahead of the slab on each tower, says a spokesman for Doka.
The common podium across the site features a basement, grade level, a mezzanine, a plaza and upper plaza, with the lower three levels to be used for parking and the two plaza levels for retail outlets.
The contractor achieved an eight to 12-day cycle in the podium levels – which feature a variety of heights between 3.50 to 3.75 m with non-typical floors and different slab design and thickness – using Dokaflex tables for the slab construction, says the spokesman.
Once clear of the podium and working on each tower, Al Shafar has been able to achieve a reduced slab cycle of seven to eight days depending on the floor being cast and six to seven days for the core shafts.
Typical floor heights of 3.4 m are being poured using the Doka Top 50 system. Comprising just three components – timber formwork beams, steel walings and formwork sheets, the system is proving ideal for the project since all parts are reusable and can be optimised for most shapes and sizes, points out the spokesman.
The system is also being used for the core shaft walls and includes telescopic shaft beams and Doka-type 150F climbing brackets.
For slab construction throughout the Sector 6 contract, Al Shafar has opted for the proven Dokaflex tables system. As ready-assembled tables, the system can be shifted in one piece to the next position without being dismantled. With fewer separate parts, formwork erection and striking are greatly accelerated ensuring the shortest possible forming times for large areas of floor.
Throughout construction, safety has been paramount to Al Shafar with Doka providing climbing scaffolds and platforms to ensure that all formwork, steelwork, cleaning and casting is done in a protected and safe environment; allowing the labourers to work with enhanced productivity, he adds.

Craneage Duties
For tower 1 of the project, Al Shafar opted for two new Liebherr 112HC-L luffing jib cranes, which were purpose-ordered through local distributor Inma, for use on only the second project in the UAE to feature the crane.
Previously the first two units had been installed on Dubai’s fourth tallest tower, the 269 m-high 21st Century Tower on Sheikh Zayed Road for the Al Rostamani Pegel – Arabtec joint venture.
On the JBR project, both Liebherr 112HC-L luffing jib cranes feature an under-hook height of 240 m. The cranes have been designed for work on exceptionally tall buildings or on sites with restricted space, says a spokesman for Liebherr.
With the steep luffing jib angle (15 to 70 degrees), these cranes are able to avoid on-site obstructions with other working areas and slew through 360 degrees under load at only 7 m slewing radius.
Featuring a compact slewing radius, the 112HC-Ls are ideal where several cranes have an overlapping slewing radii, the spokesman points out.
Both cranes are climbing with the building’s concrete pouring cycle, with one floor being completed every six to seven days. The cranes are ‘jacked-up’ to remain on the upper construction level, floor climbing within the building’s core-shaft to the final height of the tower.
“Al Shafar opted for the luffing jibs because of the limited space on Tower 1, even though it occupies the biggest area,” says Narouze.
“It is also close to the road and cannot therefore swing across the road since it would interfere with the other sectors,” he adds.
Craneage duties on the remainder of Al Shafar’s Sector 6 project is provided by six Liebherr eight-tonne-capacity tower cranes.
The project also features two 44-storey towers and a 26-storey tower linked together by a 40-storey building. All four towers and the ‘link’ building feature a four-storey podium and final heights vary between 107 – 172 m.

Passenger hoists
To ensure fast and efficient movement of the labour force and materials for the four tower and link high-rise development, Al Shafar purpose-ordered six twin-cage Alimak Scando FC24/32TD passenger/materials, once again through local distributor Inma.
The installation of the Alimak hoists has increased the efficiency of passenger movement on each of the towers and also relieved the tower cranes for some of the materials.
The Scando FC24/32TD with three motors features a 2,400 kg capacity and can travel at a speed of 0 to 57 m/min for a lifting height of up to 150 m. The car has dimensions of 1.5 m by 3.2 m by 2.15 m.
On completion, the project will contain 770 apartments with a mix of one to four bedrooms with penthouses and loft houses on the upper floors. In all, the project is expected to have 20 different types of flats.