Built-Up Beam Moment Splice
Built-Up Beam Moment Splice
(OP)
Hello all,
I am looking at installing a built-up beam that spans 18 ft. The problem is, I only have access to 2x6 lumber that is 12 ft long; so i have to splice them at the end somehow.
In a continuous beams, you would just splice the ends at the support post. But i do not have an intermediate support in this case.
Is it possible to create a moment connection using just nails such that the built-up beam behaves as if there is no splice in between supports?
I am looking at installing a built-up beam that spans 18 ft. The problem is, I only have access to 2x6 lumber that is 12 ft long; so i have to splice them at the end somehow.
In a continuous beams, you would just splice the ends at the support post. But i do not have an intermediate support in this case.
Is it possible to create a moment connection using just nails such that the built-up beam behaves as if there is no splice in between supports?





RE: Built-Up Beam Moment Splice
RE: Built-Up Beam Moment Splice
I've tried to justify this before, it's really not the easiest to do. Considering you're trying to do it with 2x6 depths make it even harder. You need a lot of nails to generate moment splices, 2x6 doesn't have a lot of room for nails.
RE: Built-Up Beam Moment Splice
RE: Built-Up Beam Moment Splice
Yea, using a 4-ply is adequate for ULS but im getting like almost 35 mm deflection which is a bit much.
I'm fairly confused about the this topic in general. The code specifies that the spacing between nails should be less than 4*d so that it deflects together, but if I calculate shear flow to find nail spacing, it is a LOT less.
In addition, with a lot of splices, it gets hard to visualize the load path, so I'm not really sure what forces nails are taking either...
At the splice location, if I just calculate moment assuming it is a regular beam --> then the stress due to moment My/I --> and calculate that resultant tensile force, i get a ridiculous amount of nails which i have to space over a long section. I feel like I am completely off , there's no way we need that much nails.
Any tips?
RE: Built-Up Beam Moment Splice
Dik
RE: Built-Up Beam Moment Splice
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.