Buttress Minimum Reinforcement

[Redacted]

Hi there,

I'm trying to find out what the minimum reinforcement value should be for buttresses.

A colleague mentioned 1% to me but I would like to be able to reference a code.

American/Canada/Europe codes are all fine.

Any assistance would be appreciated.

 

[driftLimiter]

I think you need to just try to classify it as one of the elements covered by ACI. Is it a column? Beam-Column? Seismic Loading? ACI may take you further into the aspect ratio, stress due to axial loads etc.

 

[KootK]

I would only apply the 1% minimum if your compressive stresses are so high that you actually require compression reinforcement to deal with them. The 1% is primarily meant to address creep induced migration of axial load into the bars. You need pretty significant axial stresses before that becomes a meaningful concerns. I suspect that wall / shear wall minimums will make sense here.

 

[KootK]

What's the situation? Retaining wall heel side? Cathedral flying?

 

[HTURKAK]

I do not remember , or at least i do not know any code which specify a structural element ( buttress or counterfort ) ..

I would like to share my past experience ,

-If buttress , it is essentially a compression element ( at the front face of a retaining wall ) and can be designed assuming T beam with variable depth,
- If counterfort , assume column element under full tension and provide additional wall ( min. web reinf).

I looked to my past documents , and one of them, CALTRANS Bridge design spec. section 5

5.6.5.4 Counterforts and Buttresses
Counterforts shall be designed as rectangular beams. In connection with the main tension reinforcement of counterforts, there should be a system of horizontal and vertical bars or stirrups to anchor the face walls to the counterfort. These stirrups should be anchored as near to the outside faces of the face walls, and as near to the bottom of the footing as practicable


I hope this respond answers to your question ..














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