[BC] Strong buildings vs open space

[Mike McCarthy]

To some extent, I agree with Robert on this one. The designers of the 
building cost reduced the floor attachment points and general 
building support to some extent by eliminating the mid-floor vertical 
columns in order to gain unobstructed floor space.  That and they 
underestimated the velocity needed for the fire suppression coatings 
to hold onto the steel and an accelerated by fuel fire.

It is widely believed that had the floor trusses not buckled and 
pancaked, the buildings would have stood, but probably would have 
needed to be demo'd in the end to the base of where the damage 
extended.  But not to the ground.

Sears Tower and John Hancock, as well as most other tall buildings 
here in Chicago do not follow that design philosophy.  Only the AON 
building here has open floors.  But the building is also a much 
smaller building and made totally of steel reinenforced concrete. Not 
open face steel.  All the major buildings here have multiple columns 
in the buildings inside the outer perimeter.  In fact, Sears is made 
of 9 very independent columns mated together for rigidity.

MM

At 03:57 PM 3/5/2007 -0500, Phil Alexander wrote
>On 5 Mar 2007 at 14:18, Robert Meuser wrote:
>
> >
> > Having lived in NYC during 9/11 and a few blackouts I clearly can see
> > what works and what does not.  I have long ago lost faith in traditional
> > engineering. It delivers too little too late. The design of the World
> > Trade center speaks to that alone.
>
>What was wrong with the design? Execution and governmental interference
>that prevented design execution had much more to do with failure. Originally,
>the buildings were designed to take a hit by fully fuelled 707-323, the
>long range version that took off with >250,000 lbs. of Jet A. That
>was the biggest thing in the air at the time, and the planes that hit
>were only somewhat bigger. If the beams had been encased in asbestos
>cement all the way to the top, the possibility of catastrophic structural
>failure would have been greatly diminished.