The core remnant: could it have survived?

First of all, the core columns were mostly ‘braced’ by floor beams and slabs. These things provide only limited bending resistance compared to the deep spandrel plates of the exterior walls.

With that said, let’s demonstrate that the core could collapse without lateral bracing.

Consider a 40 storey, 480ft remnant whose base load is just 10% of normal at 1.8 to 2.1ksi. I don’t know the gyradius, but it’s probably in the range of 1-2ft. So let’s use this handy derivative of the self-buckling equation

Slenderness² × base strain = 7.8373

Slenderness = 361 to 335

So gyradius = 1.3 to 1.4ft

FOOTNOTES
1. Wikipedia gives self buckling equation

Length³ × density × gravity × area = 7.8373 × elastic modulus × area moment of inertia

Length × area = volume

Volume × density = mass

Area moment of inertia = gyradius² × area

Mass × gravity / area = base stress

Base stress) elastic modulus = base strain

Length / gyradius = slenderness

Therefore we get

Skenderness² × base strain = 7.8373

2.The core columns were mostly made of 36 and 42 ksi steel ... Read even more

© 2018 ARCHALIEN.TV All Rights Reserved.

Send this to a friend