At night, the clear glazing of the Mashraq Bank corporate headquarters in Dubai will appear to glow. A globular boardroom can be seen hanging from the upper-level floor plates. SOM/© MIR
A new tower planned for the Dubai skyline will offer a strategic cutout, as well as stone louvers, so that it can provide shade to the interior while offering unparalleled views of the city.
September 17, 2013—Mashreq Bank has announced the winner of an international competition for the design of its new headquarters in Dubai: the global architecture, engineering, and urban planning firm Skidmore, Owings, and Merrill (SOM), LLP. The winning design is a 32-story tower comprising three sections: a square podium covering levels 1 through 8, an L-shaped structure covering levels 9 through 30 that provides a visual “cutout,” and a square structure covering the remaining levels above the cutout.
The building will be oriented to the north, which, when combined with the cutout, will enable the tower to offer an airy, elevated outdoor garden space in which to grow palm trees. Sweeping views of the nearby Sheikh Zayed Road, the Burj Khalifa to the east, and the city’s skyline will be available from the garden as well as through the floor-to-ceiling clear-glazed windows within the cutout—which are shaded by the upper floors of the building.
“The idea behind the tower form comes from a number of influences—one of the most significant is the effect of sunlight in the desert,” said Ross Wimer, FAIA, a design director for SOM, in written responses to questions posed by Civil Engineering online.
“By day the large cantilever of Mashreq Tower casts a deep shadow that protects the offices from glare and allows the form to be clearly legible,” Wimer said. “The reverse happens at night, when the illuminated clear glass surface of the courtyard glows like a lantern.”
The tower’s eight-story aboveground podium is located atop underground levels that are founded upon a concrete mat supported by reinforced concrete bored piles, according to James Pawlikowski, P.E., S.E., LEED-AP, M.ASCE, an associate director at SOM, who also responded in writing to questions posed by Civil Engineering online.
The 32-story tower appears to be notched, a strategy that
provides shade to the interior, views of the city, and room for an
elevated garden. SOM/© MIR
The podium will contain parking, a two-level conference center, a 350-seat auditorium, and a 100-person banquet hall, according to press materials provided by SOM. A staff dining room and cafeteria will be located on level 9, the lowest level of the L shape, and will offer direct access to the landscaped terrace.
The tower’s lateral system is created by a reinforced-concrete core wall system, which extends up the corner of the L-shaped floor plan to create two large wings on either side. The concrete core is combined with two braced frames located on each floor at the ends of the wings, according to Pawlikowski. Reinforced concrete flat slabs with drop panels comprise the floor framing system and are supported by reinforced-concrete columns located on a 9 by 9 m grid, he noted.
The corporate headquarters offices will be located at the top of the building, where the tower once again will offer a square floor plate, Wimer noted. Because the majority of the structural supports for the cantilevering portions of these floors are located in the roof, open floor plans are possible. The executive offices will be arranged around the perimeter of the tower with lounge and informal meeting spaces located within an interior ring. A boardroom will be located in the center of the plan, “suspended like a jewel from the surrounding structure and visible from the street below,” according to the press material.
To support the portions of the top levels of the tower that cantilever beyond the footprint of the L-shaped floor plan, the engineers designed a system of 27 m long cantilevered structural steel trusses that are located within the mechanical, electrical, and plumbing roof space at the top of the tower, Pawlikowski noted.
“Hangers are provided from these trusses to support the two full floor plates below,” Pawlikowski said. “Diagonal braces are provided within the horizontal floor zone at the top and bottom of the trusses, as well as at the perimeter vertical extents of the trusses, in order to tie the trusses to the core wall system, to reduce steel quantities and deflections. The result is an efficient system, as members have been provided only where required to follow the optimum load path.”
A series of horizontal and vertical stone shading louvers will articulate both sides of the building’s facade as it faces the sun, limiting the tower’s interior exposure to the sun during the workday and offering an exterior face that will read differently to viewers depending on their location. “The use of stone on the facade is one of the more unusual aspects of the design,” Wimer said. “Dubai is famous for glass and steel buildings that are meant to look futuristic.” The use of stone will provide a “more classic” appearance than is usually seen in the city, Wimer said, “and the dynamic play of shadows cast by the stone frames will give the surface a unique quality.” He added that there is an added benefit in that, as a material, stone performs better in a hot environment than glass and steel.
A series of horizontal and vertical stone shading lovers will
articulate both sides of the building’s facade as it faces the sun,
limiting the interior’s exposure to the sun during the workday and
improving the tower’s heating, ventilation, and air-conditioning
performance. © SOM
The shading provided by the louvers and by the building’s shape will also improve the building’s heating, ventilation, and air-conditioning performance. “Limiting the amount of glare from the sun allows for a better work environment,” Wimer said. “And since the heat of direct sun is also not allowed to enter the office space, air-conditioning demands are diminished.”
The building will join existing SOM-designed structures in the city, including the famed Burj Khalifa, currently ranked as the world’s tallest building at 828 m and 163 floors; the concrete Cayan Tower, which was formerly known as Infinity Tower and ranks as the world’s 59th tallest tower at 307 m and 73 stories; and the concrete Rolex Tower, measuring 247 m tall with 59 floors. (See the two-part feature article, “The Burj Khalifa Triumphs,” Civil Engineering, March 2010, and the feature article “Higher and Higher: the Evolution of the Buttressed Core,” Civil Engineering, October 2012.)