Torsion in Wood Members
Torsion in Wood Members
(OP)
I recently designed a simple wood framed square building that is going to be used for retail space. Therefore, the front of the building has a lot of large openings for store fronts (span = 20' and roof trusses bear on store front wall). I used steel tubes for my beams and columns at the store front because there is ~10' of brick above the openings and the induced torsion from the brick would cause a wood beam to fail.
Now the same owner/architect wants to build the same building in a different location, but is using thin brick on the store front side to hopefully eliminate the need for the steel beams and columns. They would like to use an LVL with an angle bolted to the face to carry the brick. Has anybody ran into this situation before? I can't seem to find any references for this that provide much help. Also, let's say the wood beam CAN resist the additional torsional load, how would the connection at the wood beam to wood column be without having to use steel plates to resist the end torsion reactions that would induce a moment into the column? I have spoken with other structural engineers and it seems this is mostly avoided - but I tend to question why more than accepting it.
Now the same owner/architect wants to build the same building in a different location, but is using thin brick on the store front side to hopefully eliminate the need for the steel beams and columns. They would like to use an LVL with an angle bolted to the face to carry the brick. Has anybody ran into this situation before? I can't seem to find any references for this that provide much help. Also, let's say the wood beam CAN resist the additional torsional load, how would the connection at the wood beam to wood column be without having to use steel plates to resist the end torsion reactions that would induce a moment into the column? I have spoken with other structural engineers and it seems this is mostly avoided - but I tend to question why more than accepting it.






RE: Torsion in Wood Members
RE: Torsion in Wood Members
RE: Torsion in Wood Members
If it were thin brick veneer then sure, but not standard brick.
RE: Torsion in Wood Members
RE: Torsion in Wood Members
RE: Torsion in Wood Members
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.
RE: Torsion in Wood Members
RE: Torsion in Wood Members
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.
RE: Torsion in Wood Members
RE: Torsion in Wood Members
What I don't like is the connections. I'm not confident in my ability to detail out a wood connection that will be appropriate for transmitting that torsion in the the column. I'm sure it can be done, but it's definitely out of my comfort zone.
RE: Torsion in Wood Members
Mike McCann, PE, SE (WA)
RE: Torsion in Wood Members
Masonry supported on wood framing has generally been frowned on in the past, for a number of reasons, although I believe the IBC now allows it under certain conditions. Almost any masonry system is much stiffer than a wood lintel beam or wood back-up framing, so it will tend to try to take the load, until it starts to crack significantly, due to lintel beam deflection, etc. Obviously, thin brick veneers are lighter than a full brick veneer, but they are no less stiff for their min. thickness. I have seen these crack badly and buckle/peel/crumble right off the face of buildings where support members were too flexible for the brick veneer or where the whole building was so flexible that the thin brick tried to act as a structural shear panel.