IBC-09 equation 18-1 (embedded post) doesn't make sense 1

[shaneelliss]

Maybe I am reading the equation wrong, but when I use equation 18-1 I get a deeper foundation by increasing the post diameter. This seems backwards. If the post diameter is bigger, there should be more resistance and the depth should be less. Right?

The equation for A increases as b(post dia.) increases. Then the equation for d also increases as A increases. Is there some parenthesis missing or something? Should the equation for A be 2.34*P/(S*b) instead of 2.34*P/S*b?

 

[msquared48]

Should the equation for A be 2.34*P/(S*b) instead of 2.34*P/S*b?

YES, YES, YES, YES.

Mike McCann
MMC Engineering

 

[shaneelliss]

Wow, four yes's. And in all caps. Does that mean my question was especially dense? Oh well. Thanks for the response. I have to wonder why the equation is written in the code without the parenthesis. I checked the 2006 code and there are none there either.

 

[msquared48]

In earl;ier codes (UBC) the presentation is much clearer.

You should bet the correct answer, or at least the correct progression now. Good luck.

Oh, and no question, at least to me, well for the most part, is "dense". How's that grab ya?

Keep asking and it will be granted!

Mike McCann
MMC Engineering