Embedded pole for retaining wall 1

[ronstruc]

I am designing embedded poles using the methodology in the IBC 1805.7. The poles will be used as part of a temporary timber lagging retaining wall. Do you have to include the 1.5 factor for sliding and overturning requirement for retaining walls (1806.1) for design or does the equation stand alone without other factors?

 

[msquared48]

The equation for the pole type embedment design stands alone. No safety factors needed.

However, the load you are talking about is a uniformly varying load increasing down the length of the pole, while the model in the IBC uses an "P" load at the top opf the pole. I would make sure that the "P" load you use generates the actual moment and shear due to the soil pressure as seen by the pole if you are going to use this equation.

Mike McCann
McCann Engineering

 

[ronstruc]

I agree with you, however I need some form of documentation to convince the reviewer. Do you know of anything?

 

[msquared48]

Quote 2006 IBC Section 1805.7.2 where it states that an embedment depth "D" obtained from the equations in the section is all that is needed for stability ("the depth to resist lateral loads").

The only drawback here is the "other methods approved by the building official" part of the reference. They may rely on that quote for the safety factor requirement. I have never heard of this before.

Will keep looking. Let me know.

Mike McCann
McCann Engineering

 

[csd72]

To my understanding, all the allowable lateral pressures have a safety factor built in.