Negative Liquidity Index

[Steel1040]

I'm running some tests and coming up with a negative liquidity index on several samples. The problem is, I'm not sure how a negative liquidity index will affect the soil and even less sure about what impact this will have on the footing design. I have been doing some research and not finding a lot on negative indexes, or what to do with them, are they bad, will this cause excessive heave due to rapid expansion of the materials, etc. and etc.

 

[Erdbau]

All a negative liquidity index means is that the soil is drier that the plastic limit. Yes, if you have expansive soils, the soil can swell if wetted. But what kind of soil do you have and what is the particular application/problem?

 

[Steel1040]

The soil is a highly weathered shale, with some trace iron streaks/nodules and the application is this soil layer is directly under a footing for a single story commercial structure to be used for a warehousing emergency vehicles. So would it be wise/reccomended to run a swell tests on the material, since once excavated for the footing, the material will now be (nearly) directly exposed to moisture infiltration from rainfall events since the backfill material will more than likely be highly permeable until it has completely consolidated itself.

 

[Steel1040]

What I am primarily concerned with is the term re-molded...as in "the soil cannot be remolded" from terzaghi: Does this refer to the sample taken to the lab? the soil in the field with regards to workability, compaction, etc? This is where my initial question about what design parameters does this affect came from.