Dubai, United Arab Emirates

Tall Emblem Structure in Za’abeel Park

Vertical Capsules

CHOICE OF PROJECT SOLUTIONS: MATERIALS AND TECHNICAL SOLUTIONS

The design of the tall structure is in the shape of a paraboloid of revolution that, just like the vortex of the sandstorm in the desert, twists from the earth up to the sky. The geometry of the paraboloid is defined by two circles united by means of slanting lines that create a curve. In this particular case, the two circles – the ground floor and the top floor – have a diameter of 60 metres and are linked by 42 pillars in reinforced concrete whose circular cross-sections have a diameter of 1.40 metres. The pillars intersect each other, creating the load-resisting structure of the tower, rising to a height of 170 metres as envisaged. Onto this seemingly complex yet simple structure, our project plans to add a cableway system consisting of a total of 12 capsules holding 8-10 people each, at a distance of 25 metres from each other and moving at a speed of 0.20 m/sec. This will be made possible by using two slanting pillars of the structure as two tracks on which there will be a mechanical drive (for example similar to that of a roller coaster), but specially designed for that purpose. The capsules will also be designed and adapted to the design of the tower and will be transported by means of this system. The capsules are secured to the two tracks by means of two mechanical arms created with hydraulic rams that will adapt more easily to all the positions of the cages which, moving along the pillars, will follow a spiral route with a rotation of about 180 degrees in relationship to their starting point. This drive system will be completed by another drive mechanism that will permit the capsules to move in a horizontal direction. Unlike the first system, this one does not need to be specially made for the tall structure of the project since it is currently in use in ski-lift systems. Just like the way a typical cableway works, this system gives access to the cages on the horizontal level that reduce their speed to 0.12 m/sec. after they have been released from the vertical drive. In this way they guarantee visitors easy access. It is important to remember that each area with access to the capsules will be controlled by staff in charge of guaranteeing safety as well as by appropriate devices. Most importantly the entry/exit area to and from the horizontal route of the capsules at a level of 166m will be protected by a metal grille to prevent any possible falls. The automatic drive system will receive the energy it requires for functioning from the sun. In fact a rotating platform consisting of PV panels, red in colour, will be set up between the two pillar-tracks along which the cages move. These panels will be used in the glass walls that demarcate the area of the drive system horizontal to the ground floor. The PV panels in silicon crystals on a red background have a maximum capacity of 1.08 KW and, when distributed over an area of about 2000 sq.m., a total of about 1300 KW is obtained. Considering that an average cableway system can use up to 700 KW, we are easily able to cover the amount of energy necessary for our system of automatic transport. The red colour of the panels is an aesthetic choice to suitably indicate the route of the capsules along the tall structure, making our project proposal even more interesting. All the systems for the running of the tower are located the basement, mainly intended as an exclusive parking area for employees. The floors of the intermediate floor and the café will be made of reinforced concrete enclosing the external pillars. There is also a double ceiling for the electrical and cooling systems to pass through. The central cylinder will house the lifts and the emergency staircase (width=1.30m) and consists of a structure in steel and glass, supported by four pillars in reinforced concrete. The closed area on the ground floor intended for the children’s library and the conference space is covered by a lowered domed vault created in steel and glass and protected by automatic moveable solar shading which allows the natural light of the sun’s rays to enter but not to heat the interior. Glass has also been chosen for the walls, decorated with mosaics in layers of colours in order to obtain a play of natural light within the internal spaces.

In this preliminary phase, we would like to emphasize that fact that the structure of the complex makes due allowances for seismic factors and the wind load that affect the city of Dubai.

DESCRIPTION OF FUNCTIONAL SPACES

Within the area destined for the project of the Za’aabel Park competition marked by the yellow line, the tall structure is positioned on the diagonal that goes from the intersection of 21st Street and 6th Street towards the centre of the lake. This has allowed the project to avoid any type of demolition of the existing paths and services in order to preserve the present day situation unchanged as much as possible. Entering the park and following the main road inside, one arrives at the base of the tower, which consists of a large circular square bordered by the pillars of the load-resisting structure with the pavilion at the centre with spaces for the library, conference rooms and toilets. This circular pavilion is cut in half by a passageway created in order to have free movement in the form of a path that crosses the square and becomes bigger at the centre in the area allocated to the observation lifts and the emergency stairs. The latter are enclosed in a cylinder of glass and steel that goes from the basement (the area for parking and utility systems) up to the covered terrace at a height of 166 metres. Moreover, in this square, which is the actual ground floor, we also find the area to access the external observation capsules with which one can “go up with the dawn and come down with the sunset”, with a complete circuit (without necessarily having to stop or get out at the top floor) taking about 40 minutes and offering a continuous view of the city from observation points that are always different. Another possibility to go up the tower by means of a panoramic route is the spiral stairway (width=1.80m) supported by the pillars of the structure, which goes to the intermediate floor without interruption and then continues to the top floor. It should be pointed out that the construction of the intermediate floor has been considered mainly for structural necessity and only consists of a large terrace. From an aesthetic point of view it “breaks” the considerable height of the tower. The top two floors are for the café and the outdoor viewing platforms offered by the height of the building and consist of terraces and small pedestrian bridges that pass from the pillars of the tower to arrive at the glass cylinder at the centre. One of the terraces will have a closed space: the café, which is bordered by 3 glass walls facing the internal empty space of the paraboloid. On this level we also find the large terrace where the external observation capsules arrive operated by security staff. Going up to the top floor by means of the lifts or the central stairway, one accesses the viewing platform at a height of 166 metres which offers a circular walkway for a 360° view of the city. The pillars terminate here at a height that permits us, before exceed 170mt, to have the space necessary to create the large light-ball which illuminate the upper parts of the tall structure.

CONCLUSIONS Besides having constructions that are symbols, many cities also have attractive recreational ones like, for example, the observation wheels in Vienna, London and in construction in Singapore, Beijing, Berlin. Also Dubai will have its wheel like other cities, but it is here that the reasoning behind the whole project leads us: for a city grand and spectacular all its buildings are, we believe that it deserves its very own wheel, singular and unique, just like the city that hosts it. This is what we promise to do with our project for the Tall Emblem Structure: a “vertical observation wheel” which will be found only and exclusively in Za’aabel Park, Dubai, UAE.

Europaconcorsi Beta

Tall Emblem Structure in Za’abeel Park