Retaining wall footing

[CROWN06]

rho minimum = 0.0018 x hf / ( 2 x d), where hf = height of footing and d is hf-cover. Is this formula ok as per ACI 318-05 for minimum steel to be used in concrete retaining wall footing.

 

[civilperson]

No, no width term shown and footings can be designed as Plain Structural Concrete.

 

[Lion06]

crown06-
I don't know what you mean by that formula, but I use the rho of 0.0018 for the min. Just multiply it by the hf*12 for in^2 per foot.

civil person-
I've always wondered about plain structural concrete. If, for reinforced concrete, you need T&S steel to prevent cracking, how do you prevent cracking in plain concrete? I would think that it would be a very bad thing if a plain footing cracked near the critical moment section (due to shrinkage), thereby reducing the effective S for the footing and causing it to fail.

 

[UcfSE]

EIT, check out ACI 318 22.3 code and commentary.