This individual has been in on forensics examination of just about every major structural failure in recent history.
https://www.kcestructural.com/MainMenuFolder/AboutUs.html
He's not impressed with the garage flooding at Champlain, says that kind of thing happens all the time and buildings don't fall down. A bunch of disintegrating columns don't mean much to him either. What he is looking for is a trigger event. Something that happened suddenly and shook the whole building. This most obvious trigger event the engineers are looking into is something called "punching shear in flat slabs." These never happen gracefully, they are always instantaneous, and catastrophic. In the case of Champlain Towers, the most likely candidate slab is the pool slab, and it broke loose of its supporting three columns holding up the south facing slab that fell first. The slab must have damaged the column when it fell, and the remaining columns couldn't take the sudden load shift and gave way in succession several seconds apart. Kilsheimer says a description of sounds and events by the lobby attendant are being used as a clue. Other people describe a succession of very loud thunder clap sounds. The three columns under the south face are exactly at the location of known water accumulation draining off the pool deck.
Engineering write-up shows flat slab requires double reinforcing at the junction of its column to prevent stress crack formation leading to failure. All the reinforcing at Champlain was almost certainly total rust because of the water accumulation problem.
https://civildigital.com/punching-shear-punching-shear-flat-slabs/

On Thursday, July 1, 2021 at 9:26:47 AM UTC-4, Fred Bloggs wrote:
> This individual has been in on forensics examination of just about every major structural failure in recent history.
> https://www.kcestructural.com/MainMenuFolder/AboutUs.html
> He's not impressed with the garage flooding at Champlain, says that kind of thing happens all the time and buildings don't fall down. A bunch of disintegrating columns don't mean much to him either. What he is looking for is a trigger event. Something that happened suddenly and shook the whole building. This most obvious trigger event the engineers are looking into is something called "punching shear in flat slabs." These never happen gracefully, they are always instantaneous, and catastrophic. In the case of Champlain Towers, the most likely candidate slab is the pool slab, and it broke loose of its supporting three columns holding up the south facing slab that fell first. The slab must have damaged the column when it fell, and the remaining columns couldn't take the sudden load shift and gave way in succession several seconds apart. Kilsheimer says a description of sounds and events by the lobby attendant are being used as a clue. Other people describe a succession of very loud thunder clap sounds. The three columns under the south face are exactly at the location of known water accumulation draining off the pool deck.
> Engineering write-up shows flat slab requires double reinforcing at the junction of its column to prevent stress crack formation leading to failure. All the reinforcing at Champlain was almost certainly total rust because of the water accumulation problem.
> https://civildigital.com/punching-shear-punching-shear-flat-slabs/

More eyewitness accounts of ground floor slab ( extension of pool slab under the building) , let loose first, just seconds before total collapse. This goes back to original architects who didn't specify any drainage of exterior pool slab, either via slope or scuppers or both, and the negligent approval by the city building department. The type of critical damage that ensued was hidden and unobservable by usual means, although the water accumulation was definitely observable, well known, and should have been remediated way back in 1981.
https://www.cnn.com/2021/06/30/us/champlain-towers-south-garage-pool-collapse/index.html

On Thursday, July 1, 2021 at 9:07:28 AM UTC-7, Fred Bloggs wrote:
> On Thursday, July 1, 2021 at 9:26:47 AM UTC-4, Fred Bloggs wrote:
> > This individual has been in on forensics examination of just about every major structural failure in recent history.
> > https://www.kcestructural.com/MainMenuFolder/AboutUs.html
> > He's not impressed with the garage flooding at Champlain, says that kind of thing happens all the time and buildings don't fall down. A bunch of disintegrating columns don't mean much to him either. What he is looking for is a trigger event. Something that happened suddenly and shook the whole building. This most obvious trigger event the engineers are looking into is something called "punching shear in flat slabs." These never happen gracefully, they are always instantaneous, and catastrophic. In the case of Champlain Towers, the most likely candidate slab is the pool slab, and it broke loose of its supporting three columns holding up the south facing slab that fell first. The slab must have damaged the column when it fell, and the remaining columns couldn't take the sudden load shift and gave way in succession several seconds apart. Kilsheimer says a description of sounds and events by the lobby attendant are being used as a clue. Other people describe a succession of very loud thunder clap sounds. The three columns under the south face are exactly at the location of known water accumulation draining off the pool deck.
> > Engineering write-up shows flat slab requires double reinforcing at the junction of its column to prevent stress crack formation leading to failure. All the reinforcing at Champlain was almost certainly total rust because of the water accumulation problem.
> > https://civildigital.com/punching-shear-punching-shear-flat-slabs/
> More eyewitness accounts of ground floor slab ( extension of pool slab under the building) , let loose first, just seconds before total collapse. This goes back to original architects who didn't specify any drainage of exterior pool slab, either via slope or scuppers or both, and the negligent approval by the city building department. The type of critical damage that ensued was hidden and unobservable by usual means, although the water accumulation was definitely observable, well known, and should have been remediated way back in 1981.
> https://www.cnn.com/2021/06/30/us/champlain-towers-south-garage-pool-collapse/index.html

and lack of load margin for the structure design. Sound like the developer was cutting corners in the building process.

On Thu, 1 Jul 2021 09:07:24 -0700 (PDT), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

>On Thursday, July 1, 2021 at 9:26:47 AM UTC-4, Fred Bloggs wrote:
>> This individual has been in on forensics examination of just about every major structural failure in recent history.
>> https://www.kcestructural.com/MainMenuFolder/AboutUs.html
>> He's not impressed with the garage flooding at Champlain, says that kind of thing happens all the time and buildings don't fall down. A bunch of disintegrating columns don't mean much to him either. What he is looking for is a trigger event. Something that happened suddenly and shook the whole building. This most obvious trigger event the engineers are looking into is something called "punching shear in flat slabs." These never happen gracefully, they are always instantaneous, and catastrophic. In the case of Champlain Towers, the most likely candidate slab is the pool slab, and it broke loose of its supporting three columns holding up the south facing slab that fell first. The slab must have damaged the column when it fell, and the remaining columns couldn't take the sudden load shift and gave way in succession several seconds apart. Kilsheimer says a description of sounds and events by the lobby attendant are being used as a clue. Other people describe a succession of very loud
>thunder clap sounds. The three columns under the south face are exactly at the location of known water accumulation draining off the pool deck.
>> Engineering write-up shows flat slab requires double reinforcing at the junction of its column to prevent stress crack formation leading to failure. All the reinforcing at Champlain was almost certainly total rust because of the water accumulation problem.
>> https://civildigital.com/punching-shear-punching-shear-flat-slabs/
>
>More eyewitness accounts of ground floor slab ( extension of pool slab under the building) , let loose first, just seconds before total collapse. This goes back to original architects who didn't specify any drainage of exterior pool slab, either via slope or scuppers or both, and the negligent approval by the city building department. The type of critical damage that ensued was hidden and unobservable by usual means, although the water accumulation was definitely observable, well known, and should have been remediated way back in 1981.
>https://www.cnn.com/2021/06/30/us/champlain-towers-south-garage-pool-collapse/index.html

I can take literally years to go through the permitting process in San
Francisco. Unless you hire an "expediter", in which case it can happen
overnight.

--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.

On Thursday, July 1, 2021 at 12:17:55 PM UTC-4, Ed Lee wrote:
> On Thursday, July 1, 2021 at 9:07:28 AM UTC-7, Fred Bloggs wrote:
> > On Thursday, July 1, 2021 at 9:26:47 AM UTC-4, Fred Bloggs wrote:
> > > This individual has been in on forensics examination of just about every major structural failure in recent history.
> > > https://www.kcestructural.com/MainMenuFolder/AboutUs.html
> > > He's not impressed with the garage flooding at Champlain, says that kind of thing happens all the time and buildings don't fall down. A bunch of disintegrating columns don't mean much to him either. What he is looking for is a trigger event. Something that happened suddenly and shook the whole building. This most obvious trigger event the engineers are looking into is something called "punching shear in flat slabs." These never happen gracefully, they are always instantaneous, and catastrophic. In the case of Champlain Towers, the most likely candidate slab is the pool slab, and it broke loose of its supporting three columns holding up the south facing slab that fell first. The slab must have damaged the column when it fell, and the remaining columns couldn't take the sudden load shift and gave way in succession several seconds apart. Kilsheimer says a description of sounds and events by the lobby attendant are being used as a clue. Other people describe a succession of very loud thunder clap sounds. The three columns under the south face are exactly at the location of known water accumulation draining off the pool deck.
> > > Engineering write-up shows flat slab requires double reinforcing at the junction of its column to prevent stress crack formation leading to failure. All the reinforcing at Champlain was almost certainly total rust because of the water accumulation problem.
> > > https://civildigital.com/punching-shear-punching-shear-flat-slabs/
> > More eyewitness accounts of ground floor slab ( extension of pool slab under the building) , let loose first, just seconds before total collapse. This goes back to original architects who didn't specify any drainage of exterior pool slab, either via slope or scuppers or both, and the negligent approval by the city building department. The type of critical damage that ensued was hidden and unobservable by usual means, although the water accumulation was definitely observable, well known, and should have been remediated way back in 1981.
> > https://www.cnn.com/2021/06/30/us/champlain-towers-south-garage-pool-collapse/index.html
> and lack of load margin for the structure design. Sound like the developer was cutting corners in the building process.

The standard load margin is actually very good in practice. What they did not consider was load handling deterioration margin. Things like "let's see what happens when half the rebars are in effect removed by corrosion." They're getting to the point where the law will require them to embed instrumentation into the build like they did with bridge in Minnesota over the Mississippi.
https://www.mprnews.org/story/2012/08/01/high-tech-sensors-track-performance-of-35w-bridge

On Thursday, July 1, 2021 at 12:32:13 PM UTC-4, jla...@highlandsniptechnology.com wrote:
> On Thu, 1 Jul 2021 09:07:24 -0700 (PDT), Fred Bloggs
> <bloggs.fred...@gmail.com> wrote:
>
> >On Thursday, July 1, 2021 at 9:26:47 AM UTC-4, Fred Bloggs wrote:
> >> This individual has been in on forensics examination of just about every major structural failure in recent history.
> >> https://www.kcestructural.com/MainMenuFolder/AboutUs.html
> >> He's not impressed with the garage flooding at Champlain, says that kind of thing happens all the time and buildings don't fall down. A bunch of disintegrating columns don't mean much to him either. What he is looking for is a trigger event. Something that happened suddenly and shook the whole building. This most obvious trigger event the engineers are looking into is something called "punching shear in flat slabs." These never happen gracefully, they are always instantaneous, and catastrophic. In the case of Champlain Towers, the most likely candidate slab is the pool slab, and it broke loose of its supporting three columns holding up the south facing slab that fell first. The slab must have damaged the column when it fell, and the remaining columns couldn't take the sudden load shift and gave way in succession several seconds apart. Kilsheimer says a description of sounds and events by the lobby attendant are being used as a clue. Other people describe a succession of very loud
> >thunder clap sounds. The three columns under the south face are exactly at the location of known water accumulation draining off the pool deck.
> >> Engineering write-up shows flat slab requires double reinforcing at the junction of its column to prevent stress crack formation leading to failure. All the reinforcing at Champlain was almost certainly total rust because of the water accumulation problem.
> >> https://civildigital.com/punching-shear-punching-shear-flat-slabs/
> >
> >More eyewitness accounts of ground floor slab ( extension of pool slab under the building) , let loose first, just seconds before total collapse. This goes back to original architects who didn't specify any drainage of exterior pool slab, either via slope or scuppers or both, and the negligent approval by the city building department. The type of critical damage that ensued was hidden and unobservable by usual means, although the water accumulation was definitely observable, well known, and should have been remediated way back in 1981.
> >https://www.cnn.com/2021/06/30/us/champlain-towers-south-garage-pool-collapse/index.html
> I can take literally years to go through the permitting process in San
> Francisco. Unless you hire an "expediter", in which case it can happen
> overnight.

That's true of everywhere, that's why you want to hire a local PE, who knows everyone in the department, to push the permit through.

>
>
>
> --
>
> John Larkin Highland Technology, Inc
>
> The best designs are necessarily accidental.

On Thursday, July 1, 2021 at 9:26:47 AM UTC-4, Fred Bloggs wrote:
> This individual has been in on forensics examination of just about every major structural failure in recent history.
> https://www.kcestructural.com/MainMenuFolder/AboutUs.html
> He's not impressed with the garage flooding at Champlain, says that kind of thing happens all the time and buildings don't fall down. A bunch of disintegrating columns don't mean much to him either. What he is looking for is a trigger event. Something that happened suddenly and shook the whole building. This most obvious trigger event the engineers are looking into is something called "punching shear in flat slabs." These never happen gracefully, they are always instantaneous, and catastrophic. In the case of Champlain Towers, the most likely candidate slab is the pool slab, and it broke loose of its supporting three columns holding up the south facing slab that fell first. The slab must have damaged the column when it fell, and the remaining columns couldn't take the sudden load shift and gave way in succession several seconds apart. Kilsheimer says a description of sounds and events by the lobby attendant are being used as a clue. Other people describe a succession of very loud thunder clap sounds. The three columns under the south face are exactly at the location of known water accumulation draining off the pool deck.
> Engineering write-up shows flat slab requires double reinforcing at the junction of its column to prevent stress crack formation leading to failure. All the reinforcing at Champlain was almost certainly total rust because of the water accumulation problem.
> https://civildigital.com/punching-shear-punching-shear-flat-slabs/

Here's latest video from Consult Engineer which does a real good job of analyzing the eyewitness video at the garage entrance ramp just minutes before collapse. He points out the building components visible in the video, the debris, and sites their location on the building drawing. Everything is pointing to pool deck slab letting go of its supports right at the critical 3-column support for the south facing facade that collapsed first, and right at the location of the pool deck water accumulation location. Water is coming from a broken sprinkler system pipe.
https://www.youtube.com/watch?v=ZUrHdwdZyWc

On Thu, 1 Jul 2021 10:16:19 -0700 (PDT), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

>On Thursday, July 1, 2021 at 12:17:55 PM UTC-4, Ed Lee wrote:
>> On Thursday, July 1, 2021 at 9:07:28 AM UTC-7, Fred Bloggs wrote:
>> > On Thursday, July 1, 2021 at 9:26:47 AM UTC-4, Fred Bloggs wrote:
>> > > This individual has been in on forensics examination of just about every major structural failure in recent history.
>> > > https://www.kcestructural.com/MainMenuFolder/AboutUs.html
>> > > He's not impressed with the garage flooding at Champlain, says that kind of thing happens all the time and buildings don't fall down. A bunch of disintegrating columns don't mean much to him either. What he is looking for is a trigger event. Something that happened suddenly and shook the whole building. This most obvious trigger event the engineers are looking into is something called "punching shear in flat slabs." These never happen gracefully, they are always instantaneous, and catastrophic. In the case of Champlain Towers, the most likely candidate slab is the pool slab, and it broke loose of its supporting three columns holding up the south facing slab that fell first. The slab must have damaged the column when it fell, and the remaining columns couldn't take the sudden load shift and gave way in succession several seconds apart. Kilsheimer says a description of sounds and events by the lobby attendant are being used as a clue. Other people describe a succession of very
>loud thunder clap sounds. The three columns under the south face are exactly at the location of known water accumulation draining off the pool deck.
>> > > Engineering write-up shows flat slab requires double reinforcing at the junction of its column to prevent stress crack formation leading to failure. All the reinforcing at Champlain was almost certainly total rust because of the water accumulation problem.
>> > > https://civildigital.com/punching-shear-punching-shear-flat-slabs/
>> > More eyewitness accounts of ground floor slab ( extension of pool slab under the building) , let loose first, just seconds before total collapse. This goes back to original architects who didn't specify any drainage of exterior pool slab, either via slope or scuppers or both, and the negligent approval by the city building department. The type of critical damage that ensued was hidden and unobservable by usual means, although the water accumulation was definitely observable, well known, and should have been remediated way back in 1981.
>> > https://www.cnn.com/2021/06/30/us/champlain-towers-south-garage-pool-collapse/index.html
>> and lack of load margin for the structure design. Sound like the developer was cutting corners in the building process.
>
>The standard load margin is actually very good in practice. What they did not consider was load handling deterioration margin. Things like "let's see what happens when half the rebars are in effect removed by corrosion." They're getting to the point where the law will require them to embed instrumentation into the build like they did with bridge in Minnesota over the Mississippi.
>https://www.mprnews.org/story/2012/08/01/high-tech-sensors-track-performance-of-35w-bridge

D. Chung over at University of Buffalo has been doing some interesting
work on smart materials, including concrete.

She was up for a talk on the Flying Tigers a few years ago- her mom
was a veteran, and is buried in Mount Pleasant Toronto.

https://amzn.to/2TrqIaz
--
Best regards,
Spehro Pefhany

On Thursday, July 1, 2021 at 4:29:04 PM UTC-4, Spehro Pefhany wrote:
> On Thu, 1 Jul 2021 10:16:19 -0700 (PDT), Fred Bloggs
> <bloggs.fred...@gmail.com> wrote:
>
> >On Thursday, July 1, 2021 at 12:17:55 PM UTC-4, Ed Lee wrote:
> >> On Thursday, July 1, 2021 at 9:07:28 AM UTC-7, Fred Bloggs wrote:
> >> > On Thursday, July 1, 2021 at 9:26:47 AM UTC-4, Fred Bloggs wrote:
> >> > > This individual has been in on forensics examination of just about every major structural failure in recent history.
> >> > > https://www.kcestructural.com/MainMenuFolder/AboutUs.html
> >> > > He's not impressed with the garage flooding at Champlain, says that kind of thing happens all the time and buildings don't fall down. A bunch of disintegrating columns don't mean much to him either. What he is looking for is a trigger event. Something that happened suddenly and shook the whole building. This most obvious trigger event the engineers are looking into is something called "punching shear in flat slabs." These never happen gracefully, they are always instantaneous, and catastrophic. In the case of Champlain Towers, the most likely candidate slab is the pool slab, and it broke loose of its supporting three columns holding up the south facing slab that fell first. The slab must have damaged the column when it fell, and the remaining columns couldn't take the sudden load shift and gave way in succession several seconds apart. Kilsheimer says a description of sounds and events by the lobby attendant are being used as a clue. Other people describe a succession of very
> >loud thunder clap sounds. The three columns under the south face are exactly at the location of known water accumulation draining off the pool deck..
> >> > > Engineering write-up shows flat slab requires double reinforcing at the junction of its column to prevent stress crack formation leading to failure. All the reinforcing at Champlain was almost certainly total rust because of the water accumulation problem.
> >> > > https://civildigital.com/punching-shear-punching-shear-flat-slabs/
> >> > More eyewitness accounts of ground floor slab ( extension of pool slab under the building) , let loose first, just seconds before total collapse. This goes back to original architects who didn't specify any drainage of exterior pool slab, either via slope or scuppers or both, and the negligent approval by the city building department. The type of critical damage that ensued was hidden and unobservable by usual means, although the water accumulation was definitely observable, well known, and should have been remediated way back in 1981.
> >> > https://www.cnn.com/2021/06/30/us/champlain-towers-south-garage-pool-collapse/index.html
> >> and lack of load margin for the structure design. Sound like the developer was cutting corners in the building process.
> >
> >The standard load margin is actually very good in practice. What they did not consider was load handling deterioration margin. Things like "let's see what happens when half the rebars are in effect removed by corrosion." They're getting to the point where the law will require them to embed instrumentation into the build like they did with bridge in Minnesota over the Mississippi.
> >https://www.mprnews.org/story/2012/08/01/high-tech-sensors-track-performance-of-35w-bridge
> D. Chung over at University of Buffalo has been doing some interesting
> work on smart materials, including concrete.
>
> She was up for a talk on the Flying Tigers a few years ago- her mom
> was a veteran, and is buried in Mount Pleasant Toronto.

I know they used women to fly transports and to ferry aircraft from one station to another, but never heard of them being used as actual combat pilots.. Regardless, whatever she did, it was very heroic, China was a very dangerous trip.

>
> https://amzn.to/2TrqIaz
> --
> Best regards,
> Spehro Pefhany

On Thu, 1 Jul 2021 15:29:04 -0700 (PDT), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

>On Thursday, July 1, 2021 at 4:29:04 PM UTC-4, Spehro Pefhany wrote:
>> On Thu, 1 Jul 2021 10:16:19 -0700 (PDT), Fred Bloggs
>> <bloggs.fred...@gmail.com> wrote:
>>
>> >On Thursday, July 1, 2021 at 12:17:55 PM UTC-4, Ed Lee wrote:
>> >> On Thursday, July 1, 2021 at 9:07:28 AM UTC-7, Fred Bloggs wrote:
>> >> > On Thursday, July 1, 2021 at 9:26:47 AM UTC-4, Fred Bloggs wrote:
>> >> > > This individual has been in on forensics examination of just about every major structural failure in recent history.
>> >> > > https://www.kcestructural.com/MainMenuFolder/AboutUs.html
>> >> > > He's not impressed with the garage flooding at Champlain, says that kind of thing happens all the time and buildings don't fall down. A bunch of disintegrating columns don't mean much to him either. What he is looking for is a trigger event. Something that happened suddenly and shook the whole building. This most obvious trigger event the engineers are looking into is something called "punching shear in flat slabs." These never happen gracefully, they are always instantaneous, and catastrophic. In the case of Champlain Towers, the most likely candidate slab is the pool slab, and it broke loose of its supporting three columns holding up the south facing slab that fell first. The slab must have damaged the column when it fell, and the remaining columns couldn't take the sudden load shift and gave way in succession several seconds apart. Kilsheimer says a description of sounds and events by the lobby attendant are being used as a clue. Other people describe a succession of
very
>> >loud thunder clap sounds. The three columns under the south face are exactly at the location of known water accumulation draining off the pool deck.
>> >> > > Engineering write-up shows flat slab requires double reinforcing at the junction of its column to prevent stress crack formation leading to failure. All the reinforcing at Champlain was almost certainly total rust because of the water accumulation problem.
>> >> > > https://civildigital.com/punching-shear-punching-shear-flat-slabs/
>> >> > More eyewitness accounts of ground floor slab ( extension of pool slab under the building) , let loose first, just seconds before total collapse. This goes back to original architects who didn't specify any drainage of exterior pool slab, either via slope or scuppers or both, and the negligent approval by the city building department. The type of critical damage that ensued was hidden and unobservable by usual means, although the water accumulation was definitely observable, well known, and should have been remediated way back in 1981.
>> >> > https://www.cnn.com/2021/06/30/us/champlain-towers-south-garage-pool-collapse/index.html
>> >> and lack of load margin for the structure design. Sound like the developer was cutting corners in the building process.
>> >
>> >The standard load margin is actually very good in practice. What they did not consider was load handling deterioration margin. Things like "let's see what happens when half the rebars are in effect removed by corrosion." They're getting to the point where the law will require them to embed instrumentation into the build like they did with bridge in Minnesota over the Mississippi.
>> >https://www.mprnews.org/story/2012/08/01/high-tech-sensors-track-performance-of-35w-bridge
>> D. Chung over at University of Buffalo has been doing some interesting
>> work on smart materials, including concrete.
>>
>> She was up for a talk on the Flying Tigers a few years ago- her mom
>> was a veteran, and is buried in Mount Pleasant Toronto.
>
>I know they used women to fly transports and to ferry aircraft from one station to another, but never heard of them being used as actual combat pilots. Regardless, whatever she did, it was very heroic, China was a very dangerous trip.
>

The Russians had women pilots in combat. The Night Witches.

Fred Bloggs wrote:
===============
>
> > She was up for a talk on the Flying Tigers a few years ago- her mom
> > was a veteran, and is buried in Mount Pleasant Toronto.
>
> I know they used women to fly transports and to ferry aircraft from one station to another,
> but never heard of them being used as actual combat pilots.
> Regardless, whatever she did, it was very heroic, China was a very dangerous trip.

** She was a nurse.

https://en.wikipedia.org/wiki/Rebecca_Chan_Chung

...... Phil

Fred Bloggs wrote:
> On Thursday, July 1, 2021 at 9:26:47 AM UTC-4, Fred Bloggs wrote:
>> This individual has been in on forensics examination of just about
>> every major structural failure in recent history.
>> https://www.kcestructural.com/MainMenuFolder/AboutUs.html He's not
>> impressed with the garage flooding at Champlain, says that kind of
>> thing happens all the time and buildings don't fall down. A bunch
>> of disintegrating columns don't mean much to him either. What he is
>> looking for is a trigger event. Something that happened suddenly
>> and shook the whole building. This most obvious trigger event the
>> engineers are looking into is something called "punching shear in
>> flat slabs." These never happen gracefully, they are always
>> instantaneous, and catastrophic. In the case of Champlain Towers,
>> the most likely candidate slab is the pool slab, and it broke loose
>> of its supporting three columns holding up the south facing slab
>> that fell first. The slab must have damaged the column when it
>> fell, and the remaining columns couldn't take the sudden load shift
>> and gave way in succession several seconds apart. Kilsheimer says a
>> description of sounds and events by the lobby attendant are being
>> used as a clue. Other people describe a succession of very loud
>> thunder clap sounds. The three columns under the south face are
>> exactly at the location of known water accumulation draining off
>> the pool deck. Engineering write-up shows flat slab requires double
>> reinforcing at the junction of its column to prevent stress crack
>> formation leading to failure. All the reinforcing at Champlain was
>> almost certainly total rust because of the water accumulation
>> problem.
>> https://civildigital.com/punching-shear-punching-shear-flat-slabs/
>
> Here's latest video from Consult Engineer which does a real good job
> of analyzing the eyewitness video at the garage entrance ramp just
> minutes before collapse. He points out the building components
> visible in the video, the debris, and sites their location on the
> building drawing. Everything is pointing to pool deck slab letting go
> of its supports right at the critical 3-column support for the south
> facing facade that collapsed first, and right at the location of the
> pool deck water accumulation location. Water is coming from a broken
> sprinkler system pipe. https://www.youtube.com/watch?v=ZUrHdwdZyWc
>

If you take his screen shots and so a bit of gain/offset enhancement on
them, you can see the third column in the line--it's covered in debris,
including some sort of broken pipe. The debris clearly goes back
further than he can see in the unaltered video screen shots.

May God have mercy on them all.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Thursday, July 1, 2021 at 9:09:24 PM UTC-4, Phil Hobbs wrote:
> Fred Bloggs wrote:
> > On Thursday, July 1, 2021 at 9:26:47 AM UTC-4, Fred Bloggs wrote:
> >> This individual has been in on forensics examination of just about
> >> every major structural failure in recent history.
> >> https://www.kcestructural.com/MainMenuFolder/AboutUs.html He's not
> >> impressed with the garage flooding at Champlain, says that kind of
> >> thing happens all the time and buildings don't fall down. A bunch
> >> of disintegrating columns don't mean much to him either. What he is
> >> looking for is a trigger event. Something that happened suddenly
> >> and shook the whole building. This most obvious trigger event the
> >> engineers are looking into is something called "punching shear in
> >> flat slabs." These never happen gracefully, they are always
> >> instantaneous, and catastrophic. In the case of Champlain Towers,
> >> the most likely candidate slab is the pool slab, and it broke loose
> >> of its supporting three columns holding up the south facing slab
> >> that fell first. The slab must have damaged the column when it
> >> fell, and the remaining columns couldn't take the sudden load shift
> >> and gave way in succession several seconds apart. Kilsheimer says a
> >> description of sounds and events by the lobby attendant are being
> >> used as a clue. Other people describe a succession of very loud
> >> thunder clap sounds. The three columns under the south face are
> >> exactly at the location of known water accumulation draining off
> >> the pool deck. Engineering write-up shows flat slab requires double
> >> reinforcing at the junction of its column to prevent stress crack
> >> formation leading to failure. All the reinforcing at Champlain was
> >> almost certainly total rust because of the water accumulation
> >> problem.
> >> https://civildigital.com/punching-shear-punching-shear-flat-slabs/
> >
> > Here's latest video from Consult Engineer which does a real good job
> > of analyzing the eyewitness video at the garage entrance ramp just
> > minutes before collapse. He points out the building components
> > visible in the video, the debris, and sites their location on the
> > building drawing. Everything is pointing to pool deck slab letting go
> > of its supports right at the critical 3-column support for the south
> > facing facade that collapsed first, and right at the location of the
> > pool deck water accumulation location. Water is coming from a broken
> > sprinkler system pipe. https://www.youtube.com/watch?v=ZUrHdwdZyWc
> >
> If you take his screen shots and so a bit of gain/offset enhancement on
> them, you can see the third column in the line--it's covered in debris,
> including some sort of broken pipe. The debris clearly goes back
> further than he can see in the unaltered video screen shots.

Kilsheimer has found his trigger. When the slab fell, probably a punchthrough shear failure at a column, the columns lose their horizontal stabilizing support, they still have a huge vertical load in place, slab or no slab. They only need to tilt 1o or less off their vertical axis to create a huge moment on the column which creates even more tilt etc... a structural failure positive feedback loop that acts out in the blink of an eye. Hopefully they can recover slab from the column area with double reinforced mat and confirm the steel was corroded through.

>
> May God have mercy on them all.
>
> Cheers
>
> Phil Hobbs
>
> --
> Dr Philip C D Hobbs
> Principal Consultant
> ElectroOptical Innovations LLC / Hobbs ElectroOptics
> Optics, Electro-optics, Photonics, Analog Electronics
> Briarcliff Manor NY 10510
>
> http://electrooptical.net
> http://hobbs-eo.com

Fred Bloggs wrote:
> On Thursday, July 1, 2021 at 9:09:24 PM UTC-4, Phil Hobbs wrote:
>> Fred Bloggs wrote:
>>> On Thursday, July 1, 2021 at 9:26:47 AM UTC-4, Fred Bloggs wrote:
>>>> This individual has been in on forensics examination of just about
>>>> every major structural failure in recent history.
>>>> https://www.kcestructural.com/MainMenuFolder/AboutUs.html He's not
>>>> impressed with the garage flooding at Champlain, says that kind of
>>>> thing happens all the time and buildings don't fall down. A bunch
>>>> of disintegrating columns don't mean much to him either. What he is
>>>> looking for is a trigger event. Something that happened suddenly
>>>> and shook the whole building. This most obvious trigger event the
>>>> engineers are looking into is something called "punching shear in
>>>> flat slabs." These never happen gracefully, they are always
>>>> instantaneous, and catastrophic. In the case of Champlain Towers,
>>>> the most likely candidate slab is the pool slab, and it broke loose
>>>> of its supporting three columns holding up the south facing slab
>>>> that fell first. The slab must have damaged the column when it
>>>> fell, and the remaining columns couldn't take the sudden load shift
>>>> and gave way in succession several seconds apart. Kilsheimer says a
>>>> description of sounds and events by the lobby attendant are being
>>>> used as a clue. Other people describe a succession of very loud
>>>> thunder clap sounds. The three columns under the south face are
>>>> exactly at the location of known water accumulation draining off
>>>> the pool deck. Engineering write-up shows flat slab requires double
>>>> reinforcing at the junction of its column to prevent stress crack
>>>> formation leading to failure. All the reinforcing at Champlain was
>>>> almost certainly total rust because of the water accumulation
>>>> problem.
>>>> https://civildigital.com/punching-shear-punching-shear-flat-slabs/
>>>
>>> Here's latest video from Consult Engineer which does a real good job
>>> of analyzing the eyewitness video at the garage entrance ramp just
>>> minutes before collapse. He points out the building components
>>> visible in the video, the debris, and sites their location on the
>>> building drawing. Everything is pointing to pool deck slab letting go
>>> of its supports right at the critical 3-column support for the south
>>> facing facade that collapsed first, and right at the location of the
>>> pool deck water accumulation location. Water is coming from a broken
>>> sprinkler system pipe. https://www.youtube.com/watch?v=ZUrHdwdZyWc
>>>
>> If you take his screen shots and so a bit of gain/offset enhancement on
>> them, you can see the third column in the line--it's covered in debris,
>> including some sort of broken pipe. The debris clearly goes back
>> further than he can see in the unaltered video screen shots.
>
> Kilsheimer has found his trigger. When the slab fell, probably a punchthrough shear failure at a column, the columns lose their horizontal stabilizing support, they still have a huge vertical load in place, slab or no slab. They only need to tilt 1o or less off their vertical axis to create a huge moment on the column which creates even more tilt etc... a structural failure positive feedback loop that acts out in the blink of an eye. Hopefully they can recover slab from the column area with double reinforced mat and confirm the steel was corroded through.
>

The pool deck fell in several minutes before the structure pancaked, though.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Thu, 1 Jul 2021 16:31:28 -0700 (PDT), Phil Allison
<pallison49@gmail.com> wrote:

>Fred Bloggs wrote:
>===============
>>
>> > She was up for a talk on the Flying Tigers a few years ago- her mom
>> > was a veteran, and is buried in Mount Pleasant Toronto.
>>
>> I know they used women to fly transports and to ferry aircraft from one station to another,
>> but never heard of them being used as actual combat pilots.
>> Regardless, whatever she did, it was very heroic, China was a very dangerous trip.
>
>** She was a nurse.
>
>https://en.wikipedia.org/wiki/Rebecca_Chan_Chung
>
>
>..... Phil

Yes, a nurse.

The eponymous 1942 movie starring John Wayne is a good example of US
propaganda films of the day. A bit light on accuracy, naturally.

--
Best regards,
Spehro Pefhany