Definition of dimensions for columns and walls - Eurocode2 3

[Pretty Girl7]

I noticed a grey-zone of the definitions of columns and walls through dimensions in Eurocode.

The clause 9.5 BS EN 1992-1-1:2004 in Eurocode, describes the following,

That means 1:4 dimension ratio = a column

That means 1:4 dimension ratio = a wall


For instance, a concrete element which has a 1 units x 4 units is both column and a wall according to Eurocode. A schrodinger's cat situation or I'm misinterpreting the definitions?
Or else, are the proper definitions of what columns are and walls are defined properly elsewhere in the Eurocodes?

 

[centondollar]

The short answer is that there is no definitive width-to-thickness ratio to characterize transition from "column" to "wall", and that is why Eurocode includes the ambiguity you mention.

There exist many methods to investigate this matter. You may run a finite element analysis (linear or non-linear with beam, shell or solid elements) to compare bending and buckling behaviour of rectangular sections with various aspect ratios, or take a look at stability textbooks (e.g., Timoshenko & Krieger) and graphs of width-to-length compared to buckling loads, or equate plate buckling and columns buckling equations to solve the required width with constant thickness (or vice versa) at which column and plate buckling occur simultaneously.

 

[Pretty Girl7]

there is no definitive width-to-thickness ratio to characterize transition from "column" to "wall", and that is why Eurocode includes the ambiguity you mention.

You're saying the Eurocode contains an "sprectum" and has "ambiguities" by default, than a definitive categorisations. Which diminishes the sole purpose of "standardization".

All the tests you have stated might be true, but that's not what my question was. So, I don't buy 100% of what you said. Then there shouldn't be different rule sets stated in the standard. But they already have.

So we have to categorise the elements as either column or a wall. Or else what's the use of providing a different set of rules in the standards. I feel like it's a typo they made if they have not stated the proper definitions elsewhere.

I will wait for a answer from other members, if I didn't receive any other, I will take as no body in this forum knows about it, that's fine

 

[Settingsun]

If it's exactly 4:1, you should satisfy both sets of requirements if you're unable to judge whether it's functioning as a column or as a wall.

 

[HTURKAK]

Dear Pretty Girl7 (Civil/Environmental),

The short answer if we strictly follow EC -2 is, we should look clause 5.3

5.3.1 Structural models for overall analysis
*****
(7) A column is a member for which the section depth does not exceed 4 times its width and the height is at least 3 times the section depth. Otherwise it should be considered as a wall...






Tim was so learned that he could name a
horse in nine languages: so ignorant that he bought a cow to ride on.
(BENJAMIN FRANKLIN )

 

[CovertShear]

As opposed to rigid boundaries, Codes are to be taken as guidelines.

You will find many ambiguities throughout Codes.

Hell, are we engineers or chefs following a "cookbook"?

 

[GeorgeTheCivilEngineer]

Also the Eurocodes have some quite open 'principle' based clauses. The intention is to not limit innovation and allows for the variability across the whole of Europe.

... which has the significant downside of needing National Annexes to tidy things up.

 

[Pretty Girl7]

Dear Pretty Girl7 (Civil/Environmental),

The short answer if we strictly follow EC -2 is, we should look clause 5.3

5.3.1 Structural models for overall analysis
*****
(7) A column is a member for which the section depth does not exceed 4 times its width and the height is at least 3 times the section depth. Otherwise it should be considered as a wall...

Thanks a lot, this was the exact clause I was looking for.

 

[Pretty Girl7]

Moreover, thanks to @CovertShear and @GeorgeTheCivilEngineer for your comments.