Given the end result, where people lost their life, this is an inexcusable and unacceptable result.
Having said that, something to consider: If you have never worked for a contractor or on a project where you are responsible for project execution, then consider that something that appears black...
If the "pipe stays" were indeed almost cosmetic, then it bothers me a lot that all of the diagonals of the truss were aligned with the stays, instead of given simpler geometry.
From looking at drawing package erection procedure (page 125):
Link
* They were supposed to tension the strands in the longitudinal direction prior to setting main span and removing shoring.
* It was planned to set the main span, and 2nd span, and only then install the guys (which were 16"...
Edit: I understand the question is regarding a shear tab.
Bottom of shear tab can't "push in" the tube given the grout inside.
But, top of shear tab will "pull away" from tube, and you'll be relying on the grout in tension, right?
Like below image?
Is that supported by code? Then OK.
If not, then I'd check the flange for the same criteria as if it wasn't grouted.
As an academic consideration: If the HSS wall was really thin and a shear tab was highly loaded and wanted to rotate the HSS wall outwards, then 2" of unreinforced grout...
Its a cable stayed bridge, that weighed 940 tons (if we can accept that the news reporting is correct).
If the bridge was designed for 100psf of traffic on it, that is an additional 340 tons approximately. So, dead load is by far the dominant load.
Without knowing project details, it seems...
Josh and Koot, thanks for reinforcing the idea that the K=1 method is just a simplified conservative way of checking against the Direct Analysis Method Output results, and that i am not simply missing something about trying to understand the K=1.:
It will be interesting to see what future AISC...
HSS tubes are a slight premium to round pipes for equivalent weight, as long as the pipes are "normal" sizes. "Normal" round pipe sections are cheaper than non-standard. I would consider the even-number-sized pipes to be "normal", and the odd-size pipes to be unusual. So, a 4", 6", 8" pipe...
I understand that Euler buckling load = the load at which a purely axially loaded column becomes unstable, meaning that any lateral load applied to the column would result in huge flexure and flexure deflection. Euler buckling equations use the “effective length” to define the buckling length...
Thanks for the replies.
Relating euler buckling stress to second order effects inducing small moments is where I get lost. I understand that Euler buckling is different than having axial force on a shape with a small bend.
Euler buckling is related to what the shape would look like in the...
Say a steel pipe has rigid (moment) base, and cantilevers up 10 feet. A 5 kip weight is vertically attached at the top.
For all load cases, is K=1 as long as you use Direct Analysis Method to determine the forces?
In other words:
For "Dead load only", "Dead + Wind", etc: Because you are...
ASCE 7 is where to find wind loads for various structures.
There is something to be said for providing a reasonable product at a good price. However, in the case of your situation: The company that provides the structure should be giving you reaction loads to design for. They should not just...
That fabric is tensioned. This tension will impose loads on your steel.
The wind loads you design for need to match what will actually happen in the field. You need to confidently determine what those loads might be. If you aren't comfortable or don't have an experienced person you can work...
For beam design, the green ASD manual used the elastic section modulus S for steel design. The 13th AISC edition uses the plastic section modulus Z for steel design.
So you're getting an extra strength capacity per the new code, which relies on the "outer" fibers yielding until the whole...
Looking only at the local strength capacity (not bending, shear, or torsion of the overall pipe) of the wall of the 24” diameter pipe in the attached simple sketch, is the ½” wall thickness acceptable?
Or alternatively, what are the local failure modes at the plate attachment point of the pipe...
metengr: To answer your question about why less testing may be required for pre-qualified welds made by a qualified welder. Both the joint and welder have been shown to be succesfully used in the past, meaning it's likely the joints will be successfully made in the future.
For an unqualified...
Please offer your opinion on this. I have a situation that I need to resolve. Does the following seem right to you?
As a general rule, welds are either pre-qualified or qualified by test to ensure that it is possible to achieve a solid weld using that specific joint configuration. If every...
We are evaluating this API 5L PSL 2 Gr. 42 steel and whether we could use it in place of A500 Gr. B for pipes. A fabricator is telling use it is available and cheaper.
We compared the fy, fu, weldability, and will compare the Charpy V toughness. So far, there are no issues with it.
Also...
We are evaluating this API 5L PSL 2 Gr. 42 steel and whether we could use it in place of A500 Gr. B for pipes. A fabricator is telling use it is available and cheaper.
We compared the fy, fu, weldability, and will compare the Charpy V toughness. So far, there are no issues with it.
Also...
