Effective Porosity

[rockiologist]

I am trying to find any laboratory procedures to run effective porosity on some clay soils. Any help would be appreciated.

 

[jdonville]

rockologist,

How is it different than the inverse of the void ratio?

Jeff

 

[fattdad]

As taken from:

http://www.usace.army.mil/publications/eng-manuals/em1110-2-1421/entire.pdf

(Note that Effective Porosity is less Porosity - defined as the ratio of void space to the total volume of media.)

b. Effective porosity. Effective porosity n-sub-e is the
porosity available for fluid flow. The effective
porosity of a unit of media is equal to the ratio of the
volume of interconnected pores that are large enough to
contain water molecules to the total volume of the rock
or soil.

In calculating the actual flow velocity of water through porous media, Darcy's law is modified to V=ki/n-sub-e

I just gave this lecture to my hydrology class today. Now how to measure the effective porosity. . . . I guess the question is how will the information be used?

f-d

¡papá gordo ain’t no madre flaca!