USING 50% UDL load For Connection Design 7

[Kishore sk]

Hello Engineers..
I have questions from connection design for AISC, In some STRUCTURAL GENERAL NOTE they have mentioned that the beam END CONNECTIONS shall develop one half the maximum ALLOWABLE UNIFORM LOAD for the beam assuming the beam is continuously SUPPORTED LATERALLY.
And the question are:
1] We have to take 50% of UDL for their respective span from CODE ?
2] What type of Load(ex. DL/LL) will be provide for Connection Software the taken UDL load?
3]For example we take (W12x14 span of 14') and the 50% of UDL ASD is 12.4K .For this we have to assign the 12.4kip as DL or any other combinations?

THANKS IN ADVANCE..​

 

[EngDM]

I've used EngDM's method before. Very often it works, but I have had the EOR come back and reject what was done, causing (unpaid) rework under very tight time constraints. Even when it works, there's still a stupid open loop that has to be closed.

The majority of the time I use that method is for like, stair stringer connections or pedestrian ramps for portable classrooms; they never indicate what load to take or method to use when deriving load, so I just provide a reasonable maximum capacity.

 

[Once20036]

No, I`ve never worked on delegated connection designs.

I hear what you`re saying about unpaid rework and tight time constraints. Also understood that there are unreasonable engineers out there.

Ultimately, I don't always put reactions on there for the same reasons - limited budgets, tight time constraints, and increased liability (I`m much more likely to have a "good enough" connection using 50% of the load vs using the real loads)
If it takes me half a day to add the reactions and half a day to double check prior to construction, that's a day on the job that I could be working on something else.

 

[RPGs]

I've been on the delegated side many times and the UDL approach is nothing but frustrating for everyone. I've had the exact same experiences as EngDM and 271828.

Why not put the reactions on there? You have them handy.

So funny this thread comes up. Just last week on the biggest project I've ever done, for the first time ever I tried to use the UDL approach. Since I know how frustrating it can be, I spent about an hour scratching my head trying to fine tune my structural steel notes so the UDL requirement was a percentage that works everywhere economically, and then realized this is dumb and just put reactions I wanted--it took 15 minutes and left me feeling stupid for even trying.

I guess my thinking was that the UDL approach is so common in my region there has to be some benefit to it, but now I REALLY don't see it.

 

[271828]

Once20036, we are all human, so it's understandable to save myself time at the expense of someone that I don't know down the chain. In this case, the balance is pretty bad, so it causes the indigestion.

In the interest of being totally honest, the UDL approach is not a problem IF there is a note such as "Design all W8 and W10 connections for 10 kips unless noted otherwise" or a table to cover short and shallow beams, such as the following.

 

[TLHS]

I do what 271828 does but without the UDL reference at all. I just have a table that gives reactions for certain beam families. It takes two seconds, you can round up to something just below a typical 2 or 4 bolt connection and be able to use that capacity easily later without doing math, you can clearly ask for weak axis shear or T/C when you need it, and it forces you to do a quick screening of your members for dumb things. Then you can markup specific weird connections as necessary.