All engineering advice, comments,change, crticizms etc. required from tad,vrystaat, DB and others with an engineering background. Are the arches too thin? What type of cables will be required?

The file will made available in sketchup to those who want to make changes.

Cape Town International Aquatic Centre (CTIAC)
Design Stage 2

http://i129.photobucket.com/albums/p210/rfataar/1j.jpg
http://i129.photobucket.com/albums/p210/rfataar/1e.jpg
http://i129.photobucket.com/albums/p210/rfataar/1b-1.jpg
http://i129.photobucket.com/albums/p210/rfataar/1h.jpg
http://i129.photobucket.com/albums/p210/rfataar/1g.jpg
http://i129.photobucket.com/albums/p210/rfataar/1i.jpg
http://i129.photobucket.com/albums/p210/rfataar/1a-1.jpg
http://i129.photobucket.com/albums/p210/rfataar/1f.jpg

rather cool, where would the space be to put this in CT?

rather cool, where would the space be to put this in CT?

well thats my design so far.

The feasibility study which includes the proposed site(s), is being conducted by Swimming South Africa. Who knows when they'll complete that.

Mo
The structure is very well balanced in the static gravity condition. Engineering modeling would determine the ideal shape for the 2 arches but the shape is pretty much there already.

The challenge comes from the dynamic loads from wind forces and eccentric forces applied during erection. These are highly asymmetric loads.

The wind applies side end and 45deg loads. The cables required for the "side walls" would resist most of these loads. The other serious load is the wind uplift. The catenary cables supporting the roof will do nothing to resist uplift as they would simply go slack. 2 solutions - 1 is ballast like the cape town glass roof and horrendously expensive.. bad and clumsy solution. 2 are cables in the same direction as the arches tied down to the ground which go taut under upward deflection. say 3 such cables. You would have to use option 2 if it is a fabric roof. Fabric roofs must be under a permanent positive up and down tension and this is high tension otherwise they vibrate and shake in high winds. Up forces from the pipe arches. Down forces from the longitudinal cables. This is what produces the signature folded up down flik flak form of a fabric roof.

Nice design. Youve got great skill.

Please deposit fee for professional services directly into in my account. :cheers:

^^Such great knowledge and expertise we have here at SSC. Nice design BTW...would actually be nice at the Culemborg site.

Mo
The structure is very well balanced in the static gravity condition. Engineering modeling would determine the ideal shape for the 2 arches but the shape is pretty much there already.

The challenge comes from the dynamic loads from wind forces and eccentric forces applied during erection. These are highly asymmetric loads.

The wind applies side end and 45deg loads. The cables required for the "side walls" would resist most of these loads. The other serious load is the wind uplift. The catenary cables supporting the roof will do nothing to resist uplift as they would simply go slack. 2 solutions - 1 is ballast like the cape town glass roof and horrendously expensive.. bad and clumsy solution. 2 are cables in the same direction as the arches tied down to the ground which go taut under upward deflection. say 3 such cables. You would have to use option 2 if it is a fabric roof. Fabric roofs must be under a permanent positive up and down tension and this is high tension otherwise they vibrate and shake in high winds. Up forces from the pipe arches. Down forces from the longitudinal cables. This is what produces the signature folded up down flik flak form of a fabric roof.

Nice design. Youve got great skill.

Please deposit fee for professional services directly into in my account. :cheers:

do you use sketchup? or know how to?

I think option 2 will work. Or im thinking perhaps cables from the edge of the fabric roof at the arch, connected to the ground, forming the facade almost.
Another option would be a cable on the along the centre of the roof above the fabric, connected to the ground on each end?...maybe?

As for the arches, what would one see underground supporting the base of the arch?

I want the roof to be PTFE.

^^Such great knowledge and expertise we have here at SSC. Nice design BTW...would actually be nice at the Culemborg site.

Culemborg is jinxed.

^^Such great knowledge and expertise we have here at SSC. Nice design BTW...would actually be nice at the Culemborg site.

Exported the model to the Culemborg site. The colours go a bit wonky in Google Earth.

http://i129.photobucket.com/albums/p210/rfataar/T1.jpg

http://i129.photobucket.com/albums/p210/rfataar/T4.jpg

http://i129.photobucket.com/albums/p210/rfataar/T5.jpg

http://i129.photobucket.com/albums/p210/rfataar/T7.jpg

http://i129.photobucket.com/albums/p210/rfataar/T3.jpg

http://i129.photobucket.com/albums/p210/rfataar/T9.jpg

oh this aquatic center :bash: ignore my comment in MM thread, got confused there.

Good design there Mo, Vrystaad hit the nail on the head there with his analasys of the center. mind you not to sure about the arch footings, maybe the arch should bulk up nearer to the ground, or something like the Athens footings for their roof...

http://upload.wikimedia.org/wikipedia/commons/4/44/Olympic_stadium.JPG

Culemborg is jinxed.

That may be, but maybe its fortunes might change once CT station is sunk underground.

My only concern about the design...isn't the arches perhaps a bit too high? When you superimposed it on the culemborg site, really makes it seem too ambitious? Maybe scale down the elevation a smidge?

That may be, but maybe its fortunes might change once CT station is sunk underground.

My only concern about the design...isn't the arches perhaps a bit too high? When you superimposed it on the culemborg site, really makes it seem too ambitious? Maybe scale down the elevation a smidge?

I think I made it look tall on the pics due to the views I chose. When you look at it from above, it takes up a very small portion of the site.

The arch height is necessary

1. To allow for the inclusion of temporary seating for up to 15,000-20,000 spectators if major events are hosted and to ensure that each spectator can actually see the action. A lower arch height would result in a major cost to expand the venue for larger events.

The comparison I have used is the London Aquatic Centre, The red indicates a cross section of my design.

http://i129.photobucket.com/albums/p210/rfataar/crosssection.jpg

2. A minimum roof height of about 15-16m is needed to ensure that diving events can take place. Again, having to adapt the venue at a later date would increase the cost.

oh temporary stands huh? makes sense now

oh temporary stands huh? makes sense now

yip.

just got to find a reasonably cheap way to cover the sides below the arch.

Vrystaat, DB, Tad and co. What about a facade to keep the wind out. Something cost effective, easy to install but also easy to remove for a while when temporary seats are added. I was thinking of cables from the arch to the ground with some lightweight membrane attached to it?

ideas?