Presumptive Load Bearing Values

[geomane]

How are the presumptive allowable lateral pressures calculated in the IBC?

Sand, for instance, is 150 psf/ft. Is this calculated from the passive pressure divided by a safety factor?

 

[PEinc]

Not sure what IBC is thinking; but if sand is 100 pcf with Rankine Kp of 3.0 for phi = 30 degrees, and with a SF = 2.0, p_p = 100 x 3.0 / 2 = 150 psf/vf. Probably conservative.

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