Creating a moment connection for timber post base?
Creating a moment connection for timber post base?
(OP)
Working on a free standing trellis design where the client is wanting no visual connections of the framing over the top of the trellis posts. No knee-bracing either, so no clear way to create a moment connection at top of post to create frame action. Anyone looked into creating a moment connection at the base of a timber post or know of a good document to use for guidance?





RE: Creating a moment connection for timber post base?
I dont know of a reference, and maybe you could have it embedded in concret, but I don't really like that idea.
RE: Creating a moment connection for timber post base?
RE: Creating a moment connection for timber post base?
RE: Creating a moment connection for timber post base?
RE: Creating a moment connection for timber post base?
Mike McCann
MMC Engineering
RE: Creating a moment connection for timber post base?
RE: Creating a moment connection for timber post base?
You could cast the verts. in concrete, with a bark finish and color, and a few strategically placed limbs (knee braces?) as part of your connection details. Do em in fiberglas.
RE: Creating a moment connection for timber post base?
RE: Creating a moment connection for timber post base?
RE: Creating a moment connection for timber post base?
I have done a few of these. We have used an HSS base and base plate with anchor bolts that the wood column can insert into after the steel is installed. Usually you can get a pretty decent fit. We designed through bolts in a force couple for the lateral load in each direction. It has worked pretty well. Especially if they are doing stone or some other finish around the base that will cover up the steel boot.
RE: Creating a moment connection for timber post base?
That is pure bunk with PT members properly set in a dry concrete mix. Mine have been in the ground for over 30 years and I am in the wet Pacific Northwest. You will see rust on steel sooner than that!
Mike McCann
MMC Engineering
RE: Creating a moment connection for timber post base?
______________
MAP
RE: Creating a moment connection for timber post base?
Personally, for the posts I put 6" of gravel in the bottom of the hole for drainage and backfill with a dry concrete mix. None of my posts have shown any rot yet over the 30+ years of use.
Mike McCann
MMC Engineering
RE: Creating a moment connection for timber post base?
RE: Creating a moment connection for timber post base?
We've used that exact detail but typically only when dealing with glulam column and beam frames as you generally want a larger number of bolts in a square pattern to ensure fixity and here in Manitoba we can't realistically get PT lumber in anything larger than a 6x6.
RE: Creating a moment connection for timber post base?
Another time I used an embedded steel WT section with a slot cut into the wood post and thru bolted. The WT gives good bending properties in the 2 directions.
RE: Creating a moment connection for timber post base?
http://farm9.staticflickr.com/8005/7635091740_8a70...
http://st.houzz.com/simgs/9c3195420f6021e7_8-3869/...
st.houzz.com/simgs/5b414a7800aefe2c_8-5618/mediterranean-landscape.jpg