PEMB Splice Modification

[HDStructural]

Hello All,

I am working on a project where a PEMB is being modified due to future change of use causing the loads to increase. The owner knows that there is next to no additional capacity in their building and that costly reinforcement will be required to beef up the whole structure. Thankfully, the foundations are good for the increased loads.

For the roof beams, I am planning to use a cover plate on the bottom flange and angles at the top flange to reinforce the structure.



I have designed side plates for the column reinforcement, essentially turning the I shape columns into box sections. I considered reinforcing the column similar to the beams, but turning the column into a box section simplifies a lot of connections and gets rid of many reinforcing plate splices.


I am having difficulty coming up with a simple connection at the beam to column splice connection. I am planning to design reinforcement at the splice connection just for the new loads on the structure, since the original detail is good for the original loads. The existing splice connection is a bolted end plate connection.


My idea is to extend the column reinforcement plates out beyond the splice so that the beam reinforcement can be connected directly to the column reinforcement. I would use angles to connect the main beam reinforcement to the column reinforcement. See below.







Does this seem feasible to you? Any ideas for improving the detail?

 

[ldeem]

Try to stich weld the beam reinforcing. That will help reduce costs. Provide a detail on beam reenforcing splice (I usually do full pen welds)

Think about making the bottom plate wider than the beam flange. This will avoid a difficult overhead weld.

3/8" plate is pretty heavy for column reinforcement, can you get by with something smaller?

Column connection at top flange looks hard to fit up in the field. Can you use the same detail as bottom flange?

 

[straub46]

The column reinforcing plates will interfere with the building girts if they extend past the outside flange. Those inside of the girts are generally flush with the outside of the column flange.

 

[HDStructural]

Ideem: Think about making the bottom plate wider than the beam flange. This will avoid a difficult overhead weld.

Good idea. I will implement that. I was also planning to stitch weld.

3/8" plate is pretty heavy for column reinforcement, can you get by with something smaller?

3/8" is needed per calcs. The loads increase more than 100% in the columns.

Column connection at top flange looks hard to fit up in the field. Can you use the same detail as bottom flange?

Are you referring to the angle to angle weld? I could flip the angle as shown below if that is what you are referring to.

The column reinforcing plates will interfere with the building girts if they extend past the outside flange. Those inside of the girts are generally flush with the outside of the column flange.

I was planning to callout to notch the column reinf plates at the girts. They need to extend out a bit so that there is space to weld.


Come to think of it, I am not sure how the column reinf plate will be connected to the column inside flange at the splice connection.