Saturday, April 2, 2011

Thursday, March 31, 2011

Breaking news!

Great news for Prashanth, the structural designer of WAN. India won the semi final of the world cup cricket against old rival Pakistan. The final will be played next week in Mumbai with opponent Sri Lanka. Together with opponent Sri Lanka, they will play the final in Mumbai next week.

Sunday, March 27, 2011

"Light cladding"


2 scales, 2 roles, 1 concept: "light cladding"



For the cladding we have 2 extreme scales to apprach: the large span roof construction and the tiny scale of the housing.


Roof: Transparency is a key requirement in order to get the maximum of light, through the stands openings, in the cavity.


section through stands' opening


Since the cladding of the roof behaves only as a shelter, "a raincoat", efficiency is a key aspect to take into account in such a large surface. Also the concrete roof structure asks for light weight material.


We will use single layer ETFE foil to meet the requirements of transparency and light weight, and take advantage of the large span possibilities of the foil to reduce detailing and facilitate water tightness and water evacuation. This will be done by spanning the foil along the radial concrete beams and achieving the tension needed through pretensed strips in an arch shape. The self-cleaning property of ETFE also adds to the efficiency aspect.





Housing facade:


The concept for the housing facades is to get a maximum comfort by increasing daylight.


Adaptability_1_The openings will be placed according to the daylight optimization analysis, which is specially relevant in the 3-layer housing (horizontal and twisting parts).


In the vertical housing, the main light source comes from the external surfaces of the ribbon. In the north side, this surfaces will consist of a large glass window in the edge of the housing box to allow a maximum of light inside.


Adaptability_2_In the south side we will have reconfiguration possibilites for energy saving in different climate scenarios still allowing a maximum of daylight. 3 layers: glass, sun shading and single layer ETFE.



The ETFE will allow a maximum of light (95%). These top to bottom ETFE windows will be very light and easily opened according to the user's will. The ETFE will have the same tension principle as in the roof but in a much smaller scale. This shape will help against the windload both when being closed and open since they will fold in pairs avoiding a concave surface against the wind.

operability of second ETFE skin



housing south facade

Friday, March 25, 2011

Finally, the roof works!

The massive 'light' concrete roof finally performs well enough to be built!! After much iteration of curvature, height and sectional sizes, it was wonderful to see all the hoope forces acting in the structure. The maximum deflection achieved now, 316mm, is within the permissible limits for such a large span structure. The stresses are also well under control.


As u can see all the compressive stresses gradually increase towards a maximum towards the 'inner hoope'




The first image above shows the roof with a more elliptical inner ring, which resulted in a deflection of 850mm, after raising the height of the roof from 7m to 12m. A slight change in geometry, as suggested by Andrew, to make the inner ring as close to a circle as possible, and also a slight change in curvature, reduced the deflection to just 316mm. What a drastic change in deflection by only a small modification in geometry!!