Column Buckling length

[SemiPE]

Hey guys, if I have a concrete column that is abutted by brick walls on both axes can I consider my column to have zero buckling length in both directions since it is technically restrained by the brick walls from deflecting?

Like to hear your opinions on this.

 

[KootK]

So brick walls on all four sides?

In reality, I'm sure that the column would be braced. I wouldn't personally rely on it though unless I was very desperate. It takes a fair bit of strength and stiffness to brace a typical concrete column. Proving that the brick walls could do the job without crushing, shearing, or buckling could be difficult. Kinda depends how beefy those walls are I guess.

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.

 

[SAIL3]

I agree with Koot....not enough certainty in the bracing capacity of the walls

 

[JAE]

In the plane of the walls there could very well be enough restraint if the walls are tight to the column.
However, masonry walls can always be removed - or doors/windows added later by someone not aware of the structural participation of the wall.



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[SemiPE]

Nice to hear opinions, and I do agree on the points that was raised. It is I guess a matter of engineering judgement, a conservative engineer would neglect the restraining effect of the brick, on the flip side the less conservative engineer desperate to have the smallest size as possible would consider it.

Hopefully, codes could give us abit of guidance on this to inhibit arguement among engineers or engineers and builders/architects. It is really hard to defend with other non-structural engineers that the buckling length is the full height (without consideration to "k") especially when it appears in reality to be restrained by these mildly rigid architectural walls.

 

[KootK]

I had assumed that this was an evaluation of an existing structure. In new builds, I don't see many concrete columns landing at the intersection of two orthogonal structural brick walls such that there's brick tying into all four sides of the column. A couple of additional thoughts.

- Construction sequencing. I'd hate to have to tell someone that they couldn't carry on with slabs above until they'd installed brick around a particular column.

- Thrust arising from column buckling restraint. You'd want uninterrupted wall for a stretch on all sides of the column for it to serve as effective bracing.

- Accidental shear wall participation. To be effective bracing, your walls would need to be snug to your columns. That may draw undesirable shear forces to your columns under wind/seismic motion.


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.