Relocating Bracings in a frame
Relocating Bracings in a frame
(OP)
I have a project that requires cutting few opennings in different floors and that results interrupting the diagonal in the particular bay that is going to be cut for openinig. I am thinking to place a diagonal same direction in the adjacent bay. Is it sufficient to do without reanalyzing the whole thing again?
Any directions will be appreciated.
Thank you
Any directions will be appreciated.
Thank you






RE: Relocating Bracings in a frame
A sketch would vastly improve the responses so that we do not have to guess at what the bracing was intended to accomplish (in the original design).
Ralph
Structures Consulting
Northeast USA
RE: Relocating Bracings in a frame
The only way you could "just move" a structural member without worrying about it is if there was zero force in the member.
RE: Relocating Bracings in a frame
RE: Relocating Bracings in a frame
RE: Relocating Bracings in a frame
RE: Relocating Bracings in a frame
Mike McCann, PE, SE (WA)
RE: Relocating Bracings in a frame
msquared48 (Structural), well thank you for ur comment but this is not a joke and if I could move the the location of the openings I would.
RE: Relocating Bracings in a frame
My initial thought would be to reanalyze the bracing after replacing the "X" bracing with "K" bracing and make the Architect adjust some of the opening locations slightly to accommodate.
Ralph
Structures Consulting
Northeast USA
RE: Relocating Bracings in a frame
Thank you for your response.
You mention K bracings I was thinking to beef up the adjacent bracing that runs the same direction that the "to be removed" is running or Running a bracing from middle of the adjacent bracing to a corner.
Do know other options?
How does K bracing work? is one in tension and the other in compression?
Thank you
RE: Relocating Bracings in a frame
"K" bracing is a configuration that looks like a capital "K" rotated 90 degrees clockwise. The braces run from the bottom of one column at floor level to the mid-point of the beam on the floor above, then back down to the bottom of the other column. Depending on the direction of the lateral load, one will be in tension, the other in compression. It will require analysis of the beam to insure it has the required strength, or can be strengthened to accommodate the forces.
Ralph
Structures Consulting
Northeast USA
RE: Relocating Bracings in a frame
RE: Relocating Bracings in a frame
canwesteng You are correct - mia culpa on my part. My description was as intended but my terminology was incorrect.
Simply removing a portion of the bracing because of an architect's whim is usually never a trivial matter.
Ralph
Structures Consulting
Northeast USA
RE: Relocating Bracings in a frame
This would possibly negatively affect the following:
1. The floor or roof diaphragm (longer diaphragm span would possibly exceed the diaphragm strength)
2. The diaphragm to collector connections may not be adequate.
3. There may not be a collector to use.
4. The columns now associated with the new brace may not be strong enough.
5. The beam at the diaphragm may not be adequate - or the beam-to-column connection may not be adequate.
6. The new load path through a different bay now will load columns below differently - may be an issue.
7. The new load path through a different bay now will load footings below differently - may be an issue.
8. An offset or change in the brace may create an irregular structure designation (for seismic design) and create all sorts of problems.
9. etc.
When you ask a question like: How does K bracing work? is one in tension and the other in compression? it suggests to me that you don't quite understand structural engineering fully. Perhaps you need to find someone who can directly help you rather than here. Such as an experienced structural engineer perhaps? I would second msquared's advice above.
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RE: Relocating Bracings in a frame
Mike McCann, PE, SE (WA)
RE: Relocating Bracings in a frame
Removing or modifying that braced frame will affect each and every other shear element, vertical or horizontal, plus connections, in the entire structure whether you like it or not. And the entire structure may have to be brought to current code depending on the extent of the modifications. Is the owner willing to pay for that structural investigation, let alone the ripple of potential modifications?
Mike McCann, PE, SE (WA)
RE: Relocating Bracings in a frame
Maine Professional and Structural Engineer. www.fepc.us
RE: Relocating Bracings in a frame
You mentioned, "And the entire structure may have to be brought to current code depending on the extent of the modifications."
I like to learn that cutting those bracings and beefing the other existing bracing does it make me to bring it to the current code?
As a matter of fact I am placing platforms/catwalks infront of the doors.
Where can I learn about the requirements due to retrofit or modification to existing buildings?
What is the amount of modification that does not trigger brings the structures to current code?
Thank you
RE: Relocating Bracings in a frame
Maine Professional and Structural Engineer. www.fepc.us
RE: Relocating Bracings in a frame
Mike McCann, PE, SE (WA)
RE: Relocating Bracings in a frame
thank you for direction do u recall the title of the thread or the date of it so I can base my search on something that results.
Thanks