Im new here, so excuse my ignorance if I have placed this thread in the wrong place.

Does anyone know if any changes have been made in the evacuation and safety rules inside skyscrapers and highrise buildings?

I am doing a project on the Twin Towers 9/11 and wondered what effects it has had on architectual design and buildings preparation.

(just incase someone is interested, Green Univercity is doing an online study of public use of lifts in sky scrapers).


Thanks for you help
Purdy

I know Petronas and Taipei 101 reviewed their evacuation procedures very successfully in the wake of the attack. Also the reason the evacuation was so incomplete was the lack of time allowed, alongside confusion (many were told to stay put in the second tower) - the fact the towers collapsed as they did was due to the fire insulation inside not being fireproofed as it should have been annually (which involved the laborious task of getting some guy to crawl into the service ducts with a foam spray and hose the mile long web of steel struts).

Basically unlike other skrapers the Twin towers didnt support their structure on the central core, but in the steel ribbing that enclosed it. It should have been able to withstand the plane crashes, at least long enough for evacuation. However, as the fire spread so easily, and melted and punctuated the ribbing all along the entire length of the building (fires spread along the paths of least resistance eg lift shafts and service ducts, the latter being where the strength lay in the Twin Towers), thus the structures became dangerously unbalanced, leading to catastrophic collapse within minutes after they were compromised.

The fireproofing in the WTC failed due to it being blown off in the crashes. Also, it is nearly impossible to properly fireproof steel truss floor assemblies (like used in 1 and 2 WTC) and what was sprayed on was rated to withstand a regular 'office stuff' fire for as long as it would normally take a fire department crew to get in and get things under control.

I have noticed that pretty much all otherwise steel-framed buildings (at least here in the USA) are now using concrete cores. That could well be another consequence of the attack as nobody above the impact level in 1 WTC survived - ALL of the exit stairwells were severed (a couple of people did get out safely from above the impact in 2 WTC as one stairwell did remain intact).

From what I am aware of, a concrete building core is more likely to remain safe in a major fire or other related event than the core in an all-steel building.

Mike

Thanks Mike and spliff fairy.

I will print this off and add to my folder. From what Iv seen in just a few pages of research on skyscrapers, it seems America and the Arab Emeretes are doing higher buildings then in the UK ; our Highest being Canary Wharf at 50 floors.

My main project is about survival personality, but I must admit the beauty of the skyscrappers Iv seen on this website is very inspiring.

Purdy

Ps it should read Greenwich Univercity in the other post.