Canton tower & Nature
In the Guangzhou TV & Sightseeing Tower project we have attempted to shift emphasis from the conceptual to the material, towards tangible effects and spatial values. We aim to emphasise the experience, to use 'concept' as a tool for generating variation, difference and a range of spatial and material values instead of as an end in itself. We describe our methodology as evolutionary, in that we envisage many variations. Instead of serving specific requirements, our project attempts to generate ranges of qualities, in which particular qualities will be embedded more or less automatically within a whole matrix. Similar to a biological system's strategy for producing a spectrum of offspring instead of focusing all hope and energy on the production of a single specific, type we produce a range of possibilities, some of which will prove to be redund ant, others which we hope will have the strength to survive.
This approach has applied, for instance, to the production of floor-plate sizes and orientations. Each floor is different - in size, intimacy, exposure - and is designed to respond to a specific set of potential users and events. Similarly, the density of the structure, which forms the outer surface, varies over the elevation of the tower. Both floor-plate size and structural density are controlled by the two ellipses governing the structure's design, and together they generate a range of conditions. The more open structure at the top generates a transparent condition that attracts programmatic activities like observation, while the denser areas in the waist of the building provide a more intimate experience.
The thinnest waist
Over the design period of the last two years several issues have been investigated. One of the main issues the client wanted to achieve was to develop the tightest waist that was ultimately possible. Budget was of course one important factor in that. For every meter reduction of the waist the cost, was calculated, would rise exponentially, because more steel would be necessary to stiffen this relatively weak part of the tower. Another important factor was the required size of the core which was needed to fit all the required lifts, shafts and emergency staircases. The core had still to be able to be inserted into the tightest area of the waist. The size and shape of the core went over the design-period through a whole evolution: A circular core was optimized to an oval in order to fit it within the tightest waist possible. The waist consisted of a band between +270m and +300m, measuring 20.65 x 27.5m from center column to center column. Which means that taking into account a structural zone of about 3.5m; that there was only about 15.6m space across for the core to fit into, excluding tolerances required for movement of the tower.
for more info go to the canton tower information website: gztvtower.info