Aldar Headquarters Dubai

case Study

1. ALDAR HEADQUARTERS AL RAHA BEACH, ABU DHABI

2. INTRODUCTION Aldar’s headquarters is the first spherical building in the middle east, standing at approx. 121 meters in height with 23 floor levels. The building has a diameter of 120.9 meters ; its width varies from 10 meters at ends to 36.4 meters in the middle. It’s structural design consist of two central concrete core for transferring environmental lateral loads, with peripheral diagrid support columns forming the building’s envelop. The project was developed following the principles of the American system of classification of U.S Green building council LEED. ARCHITECTS : MZ ARCHITECTS LOCATION : ABU DHABI - UNITED ARAB EMIRATES PROJECT MANAGER : ALDAR LAING O'ROURKE CONSTRUCTION CIVIL, MECHANICAL AND ELECTRICAL ENGINEER : ARUP FACADE DESIGN AND CONSTRUCTION : JOSEF GARTNER TOTAL BUILT UP AREA (INCLUDING BASEMENT): 123,000 SQM COST : AED 1,000,000,000 OWNER & DEVELOPER : AL DAR PROPERTIES PROJECT YEAR : 2010

3. The Aldar HQ is situated on Al Raha Beach , a new city on the outskirts of Abu Dhabi, and will be the first part of the development to be completed and occupied on the site, which is eventually intended to house more than 120,000 people. The building is visible from the Dubai-Abu Dhabi highway, which is used by commuters and travellers in their thousands every day. LOCATION

4. CONCEPT & DEVELOPMENT Inspired by the clam shell that has a deep meaning for Abu Dhabi and the symbolism of the geometric round shape, the architect imagined two giant circular curved walls of glass that evoke an open shell . The idea of the cosmic body of man in the circle and inscribing the pentagram on the front circle , being able to locate the two points of stability , the two points at which the building will meet the earth .

5. GROUND INVESTIGATION The Aldar HQ is situated on Al Raha Beach. Foundation works began just 1 month after the design was sketched, before a full set of plans was developed by the engineers. The building is proposed on the beach so the new land formation is required. 3 million m³ sand was required to create a new land. Desert sand slides s o Marine sand is needed for the HQ. After 8 months the land of HQ was fully formed and hardened.

6. DIAPHRAGM WALL As the site is close to sea, ground water surges through the loose sand and creates an upward pressure in the foundation. For this Diaphragm Wall barrier had been created. It is a concrete barricade formed of interlocking panels which socket into the bed rock and reach 15m below the sand to hold back loose sand and surging water. The ground inside the barrier can be removed to make the foundation.

7. CONCRETE CORES The structure consists of two cores that take all load down. The twin spine rise 125 mts from the concrete slab to 23 levels. Reinforced with 6500 tons of steels, these cores transfer the load into the piles. The cores were built by two single pieces of concrete – Liquid concrete was poured into giant mould which formed the shape of the structure forming a single concrete tower without any joint.

8. ARCHITECTURAL DRAWINGS

9. THE BUILDING’S SUSTAINABLE DESIGN & STRATEGIES :   The project was developed in line with the US green building council LEED rating system. It is one of the first eco-friendly official buildings in Abu Dhabi, which is made up of recyclable kind of materials like steel, concrete and glass, and includes a district cooling plant, as well as efficient lighting and water systems. A subterranean automated vacuum waste collection system is also incorporated to reuse all the waste products of the building The first of its kind in Abu Dhabi, the system sucks rubbish directly to a local waste transfer station for recycling and compacting. The building's efficiency is classed as 82%, making it the most efficient design for the floor area. Reduced energy consumption: Reduced water consumption: Minimisation of light pollution. Use of HVAC&R and fire suppression systems which eliminate emissions that contribute to ozone depletion and global warming. Use of FSC certified wood Reduced waste generation during construction by prefabricating elements , such as toilet pods, stairs cases etc. Off-site. Control of construction activities to reduce impact on the local environment. Adoption of green housekeeping practices.

10. PROJECT DETAILS: Extensive use of digital engineering  Design team used digital engineering to create 3d models for the structure, design and mechanical, electrical and plumbing (MEP) systems An exemplary building with outstanding finishes The complex steel frame, which forms the circular elevation, is clad entirely with glass panels, including floor-to-ceiling glazing at each elevation. This means it can boast impeccable common area finishes and an impressive double-height dual-entrance lobby. The project was also developed in line with the us green building council LEED rating system and achieved silver rating. This represents a 17% reduction in total energy consumption.   Offsite construction  To help meet the deadline they manufactured precast columns, stairs, landings and factory assembled toilet modules to maximise offsite construction and accelerate the erection programme on site.

11. CONSTRUCTION STRATEGIES DIAGRID SYSTEM AIRODECK SOFFIT SUPPORT SYSTEM THE ZIPPER 1. Diagrid system   The team developed a complex external diamond-shaped steel structure , called a diagrid , which achieved the striking shape of the building. The diagrid allowed the creation of structural efficiency and stability appropriate to the circular building. This diagrid system eliminates the need for internal columns to support the building which would compromise the aesthetic appeal as well as the views from within. This improved the building's efficiency, providing layout flexibility for tenants. GRADE 60, PNS 415

12. AIRODEK SOFFIT SUPPORT SYSTEM The fact that the perimeter of the basement slabs are fully enclosed by retaining walls, combined with the irregular geometry of the slabs themselves, meant that an easy to erect, versatile soffit support system was needed. The slabs having few internal and no external drop beams, the airodek prop and panel system seemed the perfect solution. The airodek panel and prop system consists of lightweight aluminium framed plywood panels and adjustable props . Each floor was split into four pours covering approximately 600m² per pour. Due to the nature of airodek the soffit support formwork was quickly in place.

13. THE ZIPPER This building based on three sides " zipper element " as a third hand, a continuous structural glass band connecting the two main fronts creating a thin, continuous surface that is both horizontal and vertical front and side windows and roof. This lateral element, the " backbone " project structure creates a brilliant fusion between façade and roof, allowing monolithic form of the object.

14. Floors are tied into the diagonals of the grid. Two large curved HSS tubes sit at the edge of the circle to define its form Steel ring beams which span horizontally between the diagonal grid members provide stability for the structure at the edge condition of the floor

15. MATERIALS IN ALDAR HEADQUARTERS The materials used to construct the spherical building of Aldar HQ are mostly recycled glass, steel and concrete . During the construction of prefabricated elements were used to reduce waste, such as stairs, bathrooms and pillars Are used for facades tubular steel diagonal beams that are woven into the entire surface creating regular prisms where glasses are inserted. The whole is coated by this facade glass wall. The project also adopts a system of underground vacuum waste collection system that transfers the waste directly to a waste transfer station for recycling and compaction, eliminating the need for collection vehicles. This system is the first of its kind in Abu Dhabi.

16. SERVICES All the services like Toilets, ducts , elevator shafts, vents , etc are fit in the concrete core The building features the following elevators: 12 passenger elevators 2 service elevators 3 mono space elevators 1 circular hydraulic lift 2 dumbwaiters The 14 lifts in the building has developed a speed of 6 meters per second. Toilets are prefabricated blocks stacked on top of each other like Tetris blocks They were raised up and lowered into the core shaft. In the building were placed 4,000 boxes and 8,000 electric utility power transmitters meters underground.

17. GLASS FACADE The curved glass skin became one of its most complex components to be executed. In order to solve the challenge of the facade curvature, triangular pieces of flat glass combined into diamond like shapes, came together like a puzzle working with the diagrid and the highly complex geometry of the skin.