At Rest Earth Pressure Coefficients (Disregard my 2 previous threads)

[geomane]

Disregard my two previous threads.

How can I determine the at rest earth pressure coefficients Kₒ from the following info:

Depth: 18'

Soil Type: SP, SP-SM

Moist Unit Weight: 110 pcf
Submerged Unit Weight: 47.6 pcf

Soil Friction Angle (Φ): 30

Can I determine it from the unit weight and friction angle without using the formula: Kₒ = 1-sin(Φ)

I have already found the following: Rankine Earth Pressure Coefficients, Active = 0.333, and Passive = 3.00.

I also need Kₒ to figure out the equivalent fluid pressure (EFP): EFP = [effective stress X (Kₒ)] + 62.4

 

[dgillette]

Why don't you like Kₒ = 1-sin(Φ), which is empirical?

The Rankine coefficients are derived by assuming soil in yield, and I don't know of any necessary relationship between them and K_o.

DRG

 

[fattdad]

multiply the active earth pressure by 1.5. That'll be close enough!

f-d

¡papá gordo ain’t no madre flaca!