Sizing splice plates in a tower

[Binary]

I don't know if this is the right forum - perhaps better in transmission structures???

Anyway, here's the story:

My boss paid a PE structural guy to "design" a laticed tower but not "detail" it. I interpreted that to mean that I would simply be creating manufacturing drawings and determining the lengths of the diagonals using his drawing.

However, I discovered that although the PE did size the bolts for the splice plates, he did not size the plates themselves nor did he specify a bolt circle for the splice bolts.

When I called him, he said that he was only asked to "size the members." but that I can FAX him my drawings for his review.

Of course, I'd like to design the splice plate and bolt circles so that his review says "Yep, that'll work."

My question, then, is what's the general procedure for sizing the splice plates and splice bolt circles for a latticed tower? (I'm familiar with ASD & have copies of both the 2nd & 4th ed of Gaylord's Handbook and McCormac's Steel Design as references).

Again, this will ultimately be reviewed and approved (or changed) by a licensed structural engineer. I'd just like to learn in the process.

Thanks.

 

[ARIFSIDDIQUI]

sizing of the splice plate will be based on no. of bolts to be acommodated to transfer the shear it will be further depend on the how u are providing the bolts the most preferred way in tower is the staggering arrangement of the bolts.

the plate size than must be checked for bearing and tearing as per avalable codes.

further for precise u can check relevant codes of your contrty

 

[Binary]

The structural engineer has specified that there be 4 bolts (he sized 'em, too) in the splice plates.

Are you saying that the orientation of the holes with respect to the loading needs to be considered?

I've been told by my boss (who is NOT an engineer) that the splice plates should be annular with welds on both the OD of the tower leg to the top of the splice plate and then along the ID of the splice plate to the tower leg. That does not seem wise to me, though, because then the welds will be supporting the entire weight of the tower above them.

It seems better to slightly counterbore the splice plate for alignment but let the leg rest against the plate itself so that the compressive load is transmitted directly into the plate.

It's frustrating because my boss thinks that the design is completed and that "detailing" is trivial (read quick). The further I go with this the more I appreciate the phrase "The devil is in the details" and also the value of having a PE look at the final dwgs before we start cutting and welding.

 

[mxkumar]

Bracing members generally connected to leg members directly if the required bolts are one or two and if the leg can accomodated these bolts. Otherwise thro' splice plate which will be bolted to leg and bracing members. It can be inside or outside. If the bracing member can accomodate stagered arrangement it is better to have such arrangement.

 

[hnamiranian]

Normaly there is some specification for splice plate connection.
1- minimum and maximum cen-cen bolt distances.
2- Max. of shear on the connection. (No. of Bolts)
3- thick. of plate shoul be checked for bearing stress.
4- Net area of main member should be checked after chosing the bolt arrangement.