Permeability Testing Equipment

[cwallace22]

Our company is in search of some user experience tips/hints/help with purchasing, or even making, our own laboratory permeability testing equipment.

What we are really looking for is some type of apparatus that allows us to utilize split spoon sample materials from our borings and compact them into some apparatus for permeability testing. Our struggle is that we are unsure of the amount of material that we actually have (not alot from split spoon samples) for performing a permeability test. This weighs in with the obvious of wanting to have relatively accurate test results and being cost-effective. Has anyone out there performed similar tests and have some ups/downs they can share.

Thanks!

 

[oldestguy]

First off the usual sample from a SPT is small. So think about larger samples using olive jars. It may or may not be ASTM but I've run many permeability tests in my home laboratory. I used Proctor molds with a porous disc at the bottom and a plate with fitting for tubing on top. Some machining of botom plate for the disc loction is needed. Clear plastic tubing of known diameter extended up as high as possible for a big head, up the stairwell to the basement. With not much sample to test the top part of the mold gets filled with clean,coarse sand. Height measurement sticks sat alongside the upper part of the plastic tube. You can use the same set-up by cutting off Shelby tubes to sample heights of 4 to 6 inches for some soils and fit those inside the clamped porous disc below and plate with fitting on top, gasketed to the tube.

 

[fattdad]

You can take the soil from a split-spoon sample, remold it and run permeability. The question is, "will the value be useful?" That means we (the forum readers) would need to know the end game.

Remolded permeability may not represent the formation permeability. The formation may have anisotropy - for example if the soil is fluvial, sedimentary or marine in origin. In these instances various sublayers create a difference between horizontal and vertical permeability. So, are you interested in vertical flow or horizontal flow? You will not discern such matters in remolded testing.

Remolding also requires some compaction water content - I mean you are not remolding at oven-dry moisture, eh? So, Mitchell, Hooper and Campenella did research on compaction moisture content and remolded permeability. In this research, they found that soil compacted wet of optimum returns a MUCH lower permeability. Like three orders of magnitude!

So, again, what's the end game? You looking for borrow in landfill construction? May be perfect!

f-d

ípapß gordo ainÆt no madre flaca!