Soldier Pile Design

[connor61]

Good morning-

I have a question regarding soldier pile design.

In the 17th Ed of AASHTO (ASD) Fig 5.6.2A provides an equation for active earth pressure below the dredge line with a factor of 1.5.

In the LRFD Code (Fig. 3.11.5.6-1), the 1.5 has been replaced with a factor of 0.5 for this equation.

In both codes a factor of 1.5 is applied to the passive earth pressure below the dredge line.

Here are my two questions:

1. Which ACTIVE earth pressure equation is correct? The 1.5 version or 0.5?

2. Where did this earth pressure distribution come from?

Thank you for any insight you may provide.

 

[PEinc]

The older ASD value is incorrect. If you figure out the equations, you will find the mistake. I pointed this out to an FHWA principal geotech and he told me I should be using the newer LRFD manual instead of the ASD manual. In effect, he didn't address my concern for the typo on the AASHTO manual.

I'm not in my office right now so I can't look at the equation until tomorrow. Then, I could tell you how the mistake was made.

 

[PEinc]

See the atached PDF for the correct equation. I believe that the original equation mistakenly included 3b or 3 times the active earth pressure coefficient as is correctly done for the passive earth pressure.