SPIRAL BRACES CONNECT TANGENTIALLY TO THREE SURROUNDING TOWERS
Luz Vargas Architects has produced a concept design for a tall building that would dramatically change our perceptions of the skyscraper and its potential for high-rise living. The resulting design is impressive - and may even be realised in the foreseeable future.
Luz Vargas Architects has come up with a proposal for rethinking the skyscraper to improve the quality of life for users and also to redefine it visually. Vargas' striking proposal, for a group of three linked spindle-shaped structures, challenges conventional wisdom in a number of ways.
Instead of treating the building as a single monolithic volume, the design breaks it into a number of separate blocks, related by a spinal core. The conventional enclosing skin is replaced by one that ebbs and ows around the core. This in turn allows a number of elevated exterior environments to be created, therefore reducing the need for people to descend to ground level in order to interact with the outside world.
The structure consists of three towers all designed in the distinctive cocoon shape. Each 36 floors-high, they are supported by a central structural mast which has its own 'cocoon' structure and links to the other three at top and middle levels. Communal and other group activities are housed in the central cocoon.
The structure is built up from a combination of steel beams and columns. Vargas has worked with Arup and with French engineer Ingerop on the structure, which works as two inverted 3D portal frames, making it relatively independent of ground conditions.
Stability would be enhanced by the linking of the towers, compared with single structures.
Each tower structure consists of a central 1m-thick and 10m-diameter concrete cylinder that acts in compression. The spine also allows for the vertical distribution of mechanical services.
The office floors are supported by radial beams suspended from the central spine by ties. This system compresses the central spine and acts as a shear diaphragm to stabilise the structure against buckling.
The central suspended spindle connects the three towers together, giving a global behaviour to the entire structure. The central spindle serves to transfer tension and compression between the towers when working under maximum forces.
In order to achieve this objective, the central suspended spindle has a specialised structural facade whose spiral braces transfer forces directly from one connecting point to another on the surface. The f loors act as central diaphragm walls, counteracting the compressive force of this diagrid facade and preventing lateral contraction of the spindle.
The spiral braces extend out from the central spindle, and connect tangentially to the three surrounding towers. The central suspended spindle is the element that unifies the entire building through its integrated structural facade and connections.
This started as a theoretical project, but Vargas is keen to see the building completed. She is currently in discussions with the University of Beijing about the possibility of construction in China.