A little job from last week.
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Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
The hotel catwalk collapse due to poor installation/engineering. There is even a video out there of the actual collapse.
- Location
- Massachusetts
I am willing to bet those original j-bolts are just mild ungraded steel.
Fulthrotl
~Autocorrect is My Worst Enema.~
- Occupation
- E
that was a bad drop... but they didn't use the proper detail when fabbing it,
and staggered the rods where they hit the crossbars for the catwalk, instead
of running them thru unbroken. that's the part that failed, if memory serves,
not the rod couplings..... did i get the bonus point?
as for these pole base extensions, the only thing i'd have added, would have
been 4 nuts spun up a few inches above the rod couplings to lock the rods
to the new pour.... it's a clean install... you can't tell from the photos if
he sank the new cage rebar into the existing base with epoxy... extra credit
points if he did....
i overtightened one of those junk threaded rod couplers one time and it split in half. I prefer ones made from actual steel and not mystery metal.
the catwalk collapse, i read the failure analasys report on it, cliffs notes version is: several levels of catwalk were supposed to be hung from (a bunch of) single rod that passes through all levels. Couldnt assemble like this (idiots) so they cut the rods off and hung each subsequent catwalk from the one above it. This compounded the loads to the point it shouldnt have even been able to support itself. The rods passed though a box beam made from 2 sections of C channel welded together, this pulled apart and slid off the rods = a bunch of twisted metal and dead people in your hotel lobby.
the catwalk collapse, i read the failure analasys report on it, cliffs notes version is: several levels of catwalk were supposed to be hung from (a bunch of) single rod that passes through all levels. Couldnt assemble like this (idiots) so they cut the rods off and hung each subsequent catwalk from the one above it. This compounded the loads to the point it shouldnt have even been able to support itself. The rods passed though a box beam made from 2 sections of C channel welded together, this pulled apart and slid off the rods = a bunch of twisted metal and dead people in your hotel lobby.
jeremysterling
Senior Member
- Location
- Austin, TX
Forgive the dumb question. How do you bend the rebar into the appropriate size circle?
Have someone who does concrete do it for you.
that was a bad drop... but they didn't use the proper detail when fabbing it,
and staggered the rods where they hit the crossbars for the catwalk, instead
of running them thru unbroken. that's the part that failed, if memory serves,
not the rod couplings..... did i get the bonus point?
as for these pole base extensions, the only thing i'd have added, would have
been 4 nuts spun up a few inches above the rod couplings to lock the rods
to the new pour.... it's a clean install... you can't tell from the photos if
he sank the new cage rebar into the existing base with epoxy... extra credit
points if he did....
but if they DID hang the catwalks using (proper structural) coupling nuts instead of staggering the rods, it wouldnt have happened. They staggered them because they realized they couldnt hoist all the catwalks over the rods without destroying the threads. Theres a dozen different ways they could have done it....so stupid.
I totally agree he did a good job, i just hate those nuts.
and yes, you get a bonus point.
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Rewire
Senior Member
- Location
- Lake of the Ozarks
In the conduit being cut i do not see an EGC ?
- Location
- Massachusetts
Well that stinks and I do agree about mystery hardware. Some of the hardware we get seems to be made of taffy.
The rebar was outside the existing 18" base so no extra points.
The EGC was short. It's inside the EMT. I didn't just splice a short piece onto it BTW. I....uhhh...pulled a new one in from the next pole about 300' away.
The rings were leftovers from previous jobs. We generally have the full 8' x 18inch cages built and often I have to take off the bottom ring to get the cage to sit properly in the hole. I assume they have jigs set up to bend them. If I had to field bend them I would find a wooden telephone pole, strap it down, twist it around and cut it off.
Mr.Sparkle
Senior Member
- Location
- Jersey Shore
I dig!
I bet you had fun figuring that repair plan out, I would have.
I bet you had fun figuring that repair plan out, I would have.
It's better than installing recessed cans or running conduit and MC all day long.
We repair/replace poles and bases all the time using whatever method seems to work. People like to run vehicles into them. I have one coming up next week that I repaired a year ago. Someone hit it again.
A few months ago I pulled out five entire bases and relocated them.
Rewire
Senior Member
- Location
- Lake of the Ozarks
I think I only wore long pants one day this "winter"
I've been wearing "long" pants sinse I was twelve
Fulthrotl
~Autocorrect is My Worst Enema.~
- Occupation
- E
and in 90 days, he'll be starting work at 4:30 am and be done by 11 am,
just in time to get out the oilcan, and oil the hinges on the gates of hell.
"but it's a dry heat".....
LawnGuyLandSparky
Senior Member
I can assure you, in NJ and here, it is NOT a dry heat.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Look at them 1, 3, 2.I'm confused, how are the second and third photo's related?
- Status