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wood connection

wood connection

wood connection

(OP)
I don't have much experience with timber.

is this the best wood connection for this case. of course I have calculate that this pass.
I'm concerned about the cracking of timber pole with bolts almost intersecting at the middle.

I can lower one of the beams if it's better but don't want to if not required.


RE: wood connection

(OP)
pic

RE: wood connection

First Design Connection,....suggest good design text book,....Breyer's the best,....modern/Fifth addition or later with some great SE contributions. Then look to NDS and this publication which is nice,..... Link NDS Application to Technical Report No. 12 for lag screw connections.

Assuming no moment/rotation at connection/beam span short enough and beam rigid enough to not induce moment in the connection (moment may occur regardless of whether you design it as a simple span unless its truly pinned which rarely happens in the real world) and the posts are braced elsewhere,....Provided these things are considered, this looks like a feasible connection. It would not be a bad idea to staggered adjacent bolt groups an inch or more if you're worried about splitting, couldn't hurt. However, You'll be pre-drilling the threaded portion into the post as per code mins. and the shank for its full depth which will help as well. If you've got Pressure Treated members,....or just plain exterior exposure, everything is hot dipped galvanized or stainless steel. If you've got high loads, just check the modes of failure in the connection. It's all in the NDS code. If high loads again, you could call for a notch to address the gravity loading condition on the bolts, and if you want to Cadillac it, find a way to flash the seat as to avoid premature dry rot within the connection, especially if you are cutting into a pressure treated or creosoted member. Touch up cut ends and notches with preservative. Useful life twenty years, maybe twenty five no matter how you build it unless you are unusually diligent with regards to annual maintenance. If for public use, make sure to provide a maintenance plan and annual inspection requirement especially for the lag bolted connections. Maybe better yet, through bolt structures like this and try to completely offset the side connection if you can and figure a creative way to get back to a deck level if that is needed. Do your best to secure dry lumber for all members.

RE: wood connection

I would let the beams slightly into the pole (1.5" or so if available) and use two thru-bolts for each beam.

Mike McCann, PE, SE (WA)


RE: wood connection

(OP)
if i use thru bolts what is the minimum distance between the intersecting bolts? 3d?
i have nds and will look at it but i don't know if it covers intersecting thru bolts distance.
i think it only has distance between parallel thru bolts.
I'm more concerned with the splitting of pole.

i have nds and breyer's pdf and will look at it.

RE: wood connection

If you have 1/2 " thru-bolts, use a 1" separation vertically at the intersection. If the bolts are 3/4", then a 1.25" separation would be OK.

I would not be concerned with the pole splitting. I would be more concerned with the beams.

Mike McCann, PE, SE (WA)


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