Height of Plane of Equal Settlement above Top of Pipe

[cwong]

Hi, I came across the following paper at the following website. The paper indicates a numerical solution for the "Height of Plane of Equal Settlement above top of pipe (He)"(Equation 5) for Positive Projecting Installation. I was wondering if the numerical solution (Equation 5) would be applicable to Negative Projecting Installation as well. I am not sure if the equation was directly pulled out from Soil Engineering by Spangler & Handy 1982 since I don't have the book. I would like to confirm the validity of the equation as I thought parenthesis might have been missing. I would also like to get a hold of the equation for "He" in Negative Projecting Installation if anyone happened to come across a copy in tif,pdf, or any other way. Thank You very much.

Paper:
Vertical Soil Arching White Paper (125K pdf)

Website:

http://www.geosyscorp.com/noframes/technical/terraflexdocs.htm#application

Regards,
csw