long beam with camber and beam splice
long beam with camber and beam splice
(OP)
I have a very long beam 120 feet that will be spliced 2 times. I have a big deflection and may need to camber the beam.
I'm worried about camber affecting the splice. Also since it will be spliced 2 times, I will have middle beam.
I don't know how cambering works with the middle beam.
I'm worried about camber affecting the splice. Also since it will be spliced 2 times, I will have middle beam.
I don't know how cambering works with the middle beam.






RE: long beam with camber and beam splice
Maine EIT, Civil/Structural.
RE: long beam with camber and beam splice
Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin
RE: long beam with camber and beam splice
Talk to a couple local fabricators who might end up involved in the project, and ask them how they would do it. More than likely, they will cut the camber into the webs, assuming some sort of a plate girder, and then just press the flanges to the web for welding. You lay the splice out on/about the radial line which goes through the joint. On bolted joints, I believe we usually drilled the flange and web splice plates and used them as templates for the girder flanges and web drilling. Many times we laid the girders on the shop floor in a surveyed relative position or stood them at their relative elevations and completed the connection drilling.
RE: long beam with camber and beam splice
or do I have to do the connection to compensate the camber?
RE: long beam with camber and beam splice
RE: long beam with camber and beam splice
RE: long beam with camber and beam splice
I saw some online how it is presented.
Can someone comment on attached pic.
RE: long beam with camber and beam splice
RE: long beam with camber and beam splice
Below you beam elevation, draw a horiz. line and divide it into at least 10' increments (maybe 5' increments). Plot the camber (Camber Diagram) in an exaggerated scale above this horiz. line and show the camber at each increment, on the curve; not tabular, P1, P2, etc. Comment on whether this is a circular curve or can be essential straight lines/segments btwn. your defined locations. Defined camber points should occur at the splice points. Since this is made up of WF shapes, it will either be heat cambered, or more likely ‘bump formed’ on a bull dozer. That’s a large horiz. hydraulic press, a 3 point press, 2 reaction points, and a center load application cylinger, which yields the WF shape at the center force application point.
RE: long beam with camber and beam splice
RE: long beam with camber and beam splice
RE: long beam with camber and beam splice
RE: long beam with camber and beam splice
RE: long beam with camber and beam splice
I don't have to be precise with camber.
1. So I only need to put to camber heights located at 2 splice points?
2. If the beam length becomes 140 ft and I need 3 splice, I can put camber heights at 3 locations where the splices are?
3. Also my splice will be bolted splice, do I need to do anything to compensate for camber with the bolted splice detail?
RE: long beam with camber and beam splice
2. Yes
3. I don't see why you can't use bolted splices.
As these are really not beams, but rather truss chords, the splices are primarily for axial forces. You could put the splices at the panel points and incorporate the truss web member connections. You don't need full moment connections in the chords.
RE: long beam with camber and beam splice
At the splices, you might consider welding a splice plate to each of the members on opposite sides. Drill the holes in the unwelded side of the plate before shop fitting and use as a template for holes in the truss member, after the chords have been shop fitted in the correct relationship, separate them for shipping. This way you know they will fit properly at site.
I think now that you should simply put in a finished camber requirement and then check/negotiate the method preferred by your Erector and Fabricator, but with a shop fitting prior to shipping.
Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin