THEN DO IT. I've already asked you a dozen times. You keep saying your calculations are in your paper, and now you admit it's not. What's the problem? Do the calculation!
2-1 says he can't.
THEN DO IT. I've already asked you a dozen times. You keep saying your calculations are in your paper, and now you admit it's not. What's the problem? Do the calculation!
Please show me this crane. A picture would be nice.Yes, a big crane can lift 33 000 tons 3.7 metres in six seconds and for that it requires about 40 litres of diesel oil. Quite big engine, though in the crane. Explained in my article incl. calculation.
Bazant already did the calculation. He discovered that it was a very small amount of the total potential energy available. I've done my own calculation of this and confirmed his result.Hiewa said:I wonder why Nist didn't do it? It helps to retrieve some failed columns from the initiation zone also. Quite incompetent not doing either. Just saying PE/KE > SE without any calculations/evidence of any sort!
Hiewa said:You still maintain the upper block was perfectly aligned with the lower structure during the gravity collapse?
Heiwa said:100% alignment between upper block (with rigid, uniform density, mass that drives the gravity collapse!) of lower structure is an ABSOLUTE requirement for a gravity collapse, like an avalanche. If no alignment the upper block slides off the lower structure due to gravity = no gravity collapse or avalanche.
2-1 says he can't.
I think it's conspiracy theorist first engineer second. He just can't stand to let go of the good old days with the "Estonia" conspiracy.Duplicate post. See if my original just slides off it.
Let's assume the column has low slenderness ratio and will not buckle before yield. So first you have to compress elastically the column to yield! Assume it is a spring! The energy/force formula is in the article. After that it becomes a little more complex. The column will deform plastically somewhere depending on its configuration and supports, so you have to establish, where this deformation takes place.
Some more remarks, now that my irritation has subsided a bit.
1. Please show me this crane. A picture would be nice.
2. Bazant already did the calculation. He discovered that it was a very small amount of the total potential energy available. I've done my own calculation of this and confirmed his result.
3. NO HEIWA. Do not put words in my mouth. IT IS OLD AND CHILDISH. No one on this forum, EXCEPT TRUTHERS, have ever made this argument. It is a strawman. DROP IT. We assume that it is aligned because this is both favorable to collapse prevention and easier to model.
4. Completely false. For the mass to slide off the top, a force has to act on the mass. This force has to be provided by the lower structure. The only way it could do that is if the floor slab on the topmost floor of the lower block was invulnerable and sloped. It was neither.
5. You need to find a new topic to harp on. The ones you're doing right now are old and debunked.
I think it's conspiracy theorist first engineer second. He just can't stand to let go of the good old days with the "Estonia" conspiracy.
Now I'm curious.
1. What constitutes a low slenderness ratio?
2.What would be the approximate slenderness ratio of the columns in the Towers?
3. In other words: Can you justify this assumption?
4. ?? Nonsense. Sloped invulnerable floor slab? Pls use layman's terms.
Duplicate post. See if my original just slides off it.

Heiwa said:4. ?? Nonsense. Sloped invulnerable floor slab? Pls use layman's terms.
Am I right? Do I win teh interwebs?
1. No, you've failed to explain how the 30,000t magically slides off.
2. Why should we use layman's terms when you purport to be a qualified engineer?
I'm a layman, when it comes to engineering at least.
After approximately 3 seconds contemplation, I deciphered this to mean the only way for the upper block to slide off the lower would be if the floor slab it impacted was ;
1. Sloped... Objects do not slide off horizontal surfaces. and
2. Invulnerable.... Unbreakable, so that the upper block doesn't just punch through the floor slab and continue on its merry way downwards in a gravity driven progressive collapse.
Am I right? Do I win teh interwebs?
1. If it is not aligned, it will slide off. WTC2 is a better example than WTC1. Clearly seen sliding off (and defintely not by gravity alone).
Once I testified for a US Congressional committée about oil tanker safety and risks of oil pollution caused by collisions and groundings and I tried to keep it in layman's terms... But who knows? Just 40+ years experience, today.