Chamfered concrete column design (bi-axial) 2

[Pretty Girl]

I'm trying to understand and produce a design chart for chamfered columns. For biaxial bending I found the following in the book 'reinforced concrete design to eurocodes' by prab bhat (page 365). However I want to design chamfered columns. Is it possible to change the following equations to suit the chamfered area? If so how?

The one I want to design (the chamfer is too big, but this is just for illustrative purposes)

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I guess the following equation can easily be modified as all I have to do is introduce the area of the concrete.

But for the following moment equations, how to modify it to get the Mx and My.

 

[HTURKAK]

My points ,
- Chamfering 50 mm ( literally diagonal 71 mm) will compromise the cover of corner reinf. and total strength of column due to bigger cover.
- I am not sure about , how precise the calculation will be as per the method described in 'reinforced concrete design to eurocodes' by prab bhat

- IMO , the precise method would be , trial and error NA axis location using the equilibrium equations,
- I would prefer a reasonable chamfering ( say 20 mm ) and use BRESLER's method described in the EN 1992 .

..

He is like a man building a house, who dug deep and laid the foundation on the rock. And when the flood arose, the stream beat vehemently against that house, and could not shake it, for it was founded on the rock..

Luke 6:48

 

[Pretty Girl]

@HTURKAK
But the Bresler's method is only to check if the dimensions of the column is safe isn't it? as I see it doesn't provide a total design solution (with the reinforcement area + where to place them etc are missing).
The prab bhatt's book provides comprehensive solution. Only thing is that book does not show anything for chamfered or irregular shapes.

 

[hardbutmild]

But the Bresler's method is only to check if the dimensions of the column is safe isn't it? as I see it doesn't provide a total design solution (with the reinforcement area + where to place them etc are missing).

What do you mean? You can calculate if failure will occur based on provided reinforcement - it should be safe. It's an analysis tool, not a design tool so you don't get the required area of steel or their position. You can get the "position" of bars by doing independent analysis in each direction (uniaxial bending with axial load)... optimal rebar distribution shouldn't be too far off. It's trial and error, but it shouldn't be too hard to do a spreadsheet that checks Bressler for any distribution of reinforcement.

 

[HTURKAK]

@ Pretty Girl (Structural)(OP);
My points are ,
- Bresler's method is suggested at EN 1992 item 5.8.9 Biaxial bending,(4)
- You can design ( size and reinf , with a few trials ) using Bresler’s Reciprocal Load Method or Load Contour Method.
- pls look to the following doc. to get better idea and the following link

https://www.sefindia.org/forum/files/columns_biaxialother_shapes_592.pdf

....

He is like a man building a house, who dug deep and laid the foundation on the rock. And when the flood arose, the stream beat vehemently against that house, and could not shake it, for it was founded on the rock..

Luke 6:48

 

[Pretty Girl]

@hardbutmild
Thank you. I will look more into the breslers.

 

[Pretty Girl]

@HTURKAK
Thank you, I will look more into it and further go through the methods you mentioned.