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Steel truss to wood post connection 2
- Thread starter scotton
- Start date
I'd probably have a steel bearing plate on the post secured with a single through bolt about 4" down from the end of the post (side to side) to keep the bolt out of the way of the wall finishes.
-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates
-Dik
-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates
-Dik
I haven't come across this type of system before, but these are my thoughts if I were to analyze/design something similar:
[ol 1]
[li]To estimate the truss capacity, use RISA 3D or a similar frame analysis program, using the geometry and member sizes per your plan.[/li]
[li]For the connection between the PT 6x6 post and the truss, it seems like most of the load will be near the face of the post. Be sure to account for that eccentricity in checking the post capacity.[/li]
[li]Since the post is pressure treated, the portion of the truss in contact with it should be adequately protected with a membrane separation, or galvanized.[/li]
[li]Embedding a wood member in concrete is not recommended. The building code may even prohibit this, although I don't know for sure off the top of my head. If I was forced to use a similar system, I would embed steel in the concrete, which would be used to connect to the PT post. The PT post would end at or slightly above the top of concrete.[/li]
[li]Be sure to take a close look at lateral forces and how the structure will resist them.[/li]
[/ol]
This seems like an interesting system.
[ol 1]
[li]To estimate the truss capacity, use RISA 3D or a similar frame analysis program, using the geometry and member sizes per your plan.[/li]
[li]For the connection between the PT 6x6 post and the truss, it seems like most of the load will be near the face of the post. Be sure to account for that eccentricity in checking the post capacity.[/li]
[li]Since the post is pressure treated, the portion of the truss in contact with it should be adequately protected with a membrane separation, or galvanized.[/li]
[li]Embedding a wood member in concrete is not recommended. The building code may even prohibit this, although I don't know for sure off the top of my head. If I was forced to use a similar system, I would embed steel in the concrete, which would be used to connect to the PT post. The PT post would end at or slightly above the top of concrete.[/li]
[li]Be sure to take a close look at lateral forces and how the structure will resist them.[/li]
[/ol]
This seems like an interesting system.
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- #5
OP said:
I think that connection is a horrible idea:
1) For loads of significance like this, always put the framing in direct bearing over the wood post.
2) The connection creates a moment connection between the truss and the post that I doubt the post or the connection could survive. Is this intended to be moment frame construction?
3) I feel as though this setup would be pretty difficult to erect.
With 150 mph winds, uplift will be a major factor in the truss to post connection. Detail 4 may act as a moment connection, but after a while, the bolts would loosen up, so probably best to consider it a pin or roller support, which means the roof diaphragm will be expected to carry the total horizontal component of wind.
Snow load is zero and dead load is minimal, so wind is by far the most important consideration. Wind uplift must be checked and the bottom chords braced as required.
There are no particular references I know of, for analyzing these systems, but anchorage of the wood posts against uplift becomes an important item to be checked. Leaving the design of the timber posts and foundations to others is questionable in my mind, but the factored uplift at each post should be specified. Dead load resistance to uplift is virtually non-existent.
I did not notice the eve height specified. That should be shown. There are no side or end walls shown. That should be confirmed, as it makes a huge difference to the wind resisting elements. Wind bracing, if required should be shown.
Snow load is zero and dead load is minimal, so wind is by far the most important consideration. Wind uplift must be checked and the bottom chords braced as required.
There are no particular references I know of, for analyzing these systems, but anchorage of the wood posts against uplift becomes an important item to be checked. Leaving the design of the timber posts and foundations to others is questionable in my mind, but the factored uplift at each post should be specified. Dead load resistance to uplift is virtually non-existent.
I did not notice the eve height specified. That should be shown. There are no side or end walls shown. That should be confirmed, as it makes a huge difference to the wind resisting elements. Wind bracing, if required should be shown.
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