Worst Workmanship - Deficiencies - Terrible Detail (&/or interpretation) - Crazy Fixes - ETC... 2

[CELinOttawa]

In chatting on another thread, AELLC suggested this might be a fun topic. I agree.

I will get the ball rolling with the attached photo. This is meant to be a full moment, 25% shear, connection to an equal size embedded column as the base for a portal frame which supports 100% glass glazing. Warning: One cannot un-see such terrible work. Hide the kids.

 

[ajh1]

I had an interesting one many years ago. We were designing a small mechanical tower on a power plant site that because of the overall dimensions was going to have fixed base columns attached to the foundation (drilled piers with pier caps). I had a call from the field engineer at about 3pm on a Friday afternoon (always when you love to have calls of this nature). He had been wandering around the jobsite that afternoon basically killing time when the contractor called him over to where the pier cap was being worked on. He pointed out that the lower plate washer on 3 of the anchor bolts was interfering with the rebars coming up out of the pier and asked if he could cut the bars off. After some discussion between myself and the field engineer I told him to tell the contractor that he could cut 3 of the bars but no more than 2 adjacent to each other. This was obviously somewhat bogus advice in that there was only one spot on the pier circumference that had the interference problem with the 20 or so total rebars around the pier.
A couple of weeks later, again at around 3pm on a Friday afternoon, the same field engineer called me. He asked me how many bars I said the contractor could cut. I flipped the question around and asked him how many he told the contractor. He indicated he told the guy zero, figuring that if he told him 2 the guy would say how about 3, if he said 3 how about 5, etc. My next question was, how many did the contractor cut, and he told me 4 or 5 all in row. (Keep in mind this story is some 35 years old so the exact quantities are a little loose in my mind now.)
Ultimately we worked out an acceptable alternate solution so that everyone was happy, but it certainly pointed out to me, the young engineer, how much attention one needs to pay to certain details to insure that they can actually be produced in the form that we drew them.

 

[RHTPE]

I can't resist adding to this thread.

The attached photo shows the underside of an existing 2nd floor addition. This addition had been constructed in the 1960s directly over an existing one story wing that had wood rafters. The wood rafters were left in place and brick in-fill between them was used to support the yellow spreader beam. The spreader beam carried the orange girder which also carried a column above that supported the roof.

Note the crack in the masonry wall starting at the left end of the yellow spreader beam and migrating down to the upper left corner of the opening.

Apparently (as best we can determine) the owner did some remodeling after the 2nd story was completed and decided to cut in the opening you see in the masonry wall (topped by the gray channel). We do not know if the channels (one on each side of the wall) were installed before or after the opening was cut, but we suspect after. What you can't see in the photo is that the channels installed as a header did not contact the masonry - there was about a 3/4"-1" gap between the back side of the channels and the wall. The 7 bolts used to attach the channel are 1/2" expansion bolts into hollow masonry.

The only thing preventing a major collapse was that the yellow header beam rotated, its right end made contact with the girder above, and the resulting load path was through the narrow masonry column at the right side of the opening.

Thankfully the Engineer of Record for this current renovation agreed that this probably was unsafe and convinced the owner to pay for repairs. I devised a temporary support for the girder so that the spreader beam and the masonry wall below could be removed and replaced with a much larger transfer beam supported on 2 new columns.

There is nothing more adventurous for a structural engineer than solving the challenges of building renovation - especially when the client is the contractor.

Ralph
Structures Consulting
Northeast USA

 

[JAE]

RHTPE - nice!

 

[TehMightyEngineer]

That's probably my favorite one here. Really shows the importance of proper load path and the penalties for ignoring it. Amazing they thought they could do that with expansion anchors and not proper through bolts.

Maine EIT, Civil/Structural.

 

[CELinOttawa]

Or even just filling the darned hollow cores!

 

[slickdeals]

Let me share a castellated beam that I was inspecting. Needless to say, I had them shore it and weld a plate at the shear tab.

 

[kingnero]

^^^ holy shit whoever installed this should've seen that something isn't quite right there...

 

[IFRs]

slickdeals is winning this competition

 

[CELinOttawa]

Okay, I'm impressed... What span? Castellated are normally quite the span, and I am SO very glad that no one put any additional dead load on the beam!

Just WOW.

 

[PMR06]

I agree, slickdeals' example takes the cake!

Most of these things are shoddy site work, but presumably that castellated beam went thru a shop drawing review, then an fab shop, erector, etc...

I'm surprised it held up just under self weight!

 

[ColinPearson]

First pic is pretty awesome because safety first, you know? At some point after the top flange of the beam corroded off, some safety conscious individual bent it up around that piece of conduit so no one would run into it...

Second one is the condition of some of the existing structure... that used to be a W shape (WF actually, it's pretty old)

Link

Link

 

[dcarr82775]

I have never worked with castellated beams but it would seem you always run a risk of unpleasant looking section if you have to cope the top and bottom flanges. This one made worse by that wide top plate.

 

[JStephen]

I like drawing stuff to scale if I can, and work with one or two draftsman that would rather change dimensions than stretch the item to which the dimensions are attached, with sometimes humorous results. So my guess of the castellated-beam issue is that some guy drew those holes with a note that says "Continue holes to end" and never thought to lay them out to see how many fitted on there, or how they fitted.

 

[moltenmetal]

You guys sure these pics don't belong more on failblog than here?! Awful, but awesome!

 

[TehMightyEngineer]

I wonder if I can find that picture of a sign in a department store that listed the allowable floor load as 3,000 psi. It was an elevated concrete slab.

Maine EIT, Civil/Structural.

 

[jvvse]

Am I too late?

The biggest problem I came across was when a contractor demo'd an elevated concrete slab at grade and left the basement walls cantilevered. There were busy downtown streets around the entire structure, and only when my boss and the City inspector told the superintendent to get shoring on those walls immediately did he reluctantly agree to do it.

Seen lots of fun stuff on wood construction, but nothing life threatening.

 

[CELinOttawa]

Colin: I've done a lot of historical work, including some historical industrial (but, come to think of it, nearly all of that was reinforced concrete or brick), but I've not seen rusting that bad inside any building. Bridges, absolutely - And worse - BUT that should be a protected environment; Easily washed and painted intermittently. What type of shop was that? Chemical factory? Salt factory? Hot saline vapours off of open vats?

Seriously bad corrosion. I'm surprised that the rivets at 6" spacing seemed to prevent rust jacking; I would have expected it to have to be closer...

 

[JAE]

Not as crazy as slickdeal's....but gotta love plumbers:

 

[XR250]

Nice. I do love Plumbers, Electricians and HVAC Contractors. I get alot of business fixing their carpentry.

 

[ColinPearson]

CELinOttowa - FCC unit an oil refinery... Not nearly the most corrosive atmosphere in a refinery but obviously something got to it! This portion of the structure all had pyrocrete and this was the worst area we uncovered. There were several similar to it and several other places where you could have thrown a football through the web of the WF. I asked the guys what happened to the beam when I walked up there and had seen that it was removed and they told me "we took it out"... The crane had been down for that day so I asked them HOW they took it out and the guy looked at me and told me "in buckets".

Pretty interesting job altogether; we dug up a bunch of square cross section rebar which I'd never seen.