Bad Soil, Tough Site

[cieg22]

I have to come up with some rough cut/fill calcs for a conceptual meeting with a client.

We are building a parking lot and a single-story building.

We have our infiltration testing report, with soil horizons, but we don't have soil boring data yet.

In the meantime, I'm trying to use the infiltration test pit horizons for a quick reference.

The soil is listed as being AP fsl from 0-6", Fill fsl from 6"-22" and Ab fsl from 22"-34".

In your opinion, can the Fill and Ab layers remain in place if we putting the building/parking lot in that area, or should all organic material be removed?

The testing agency determined the seasonal high water table to be 52" down. However, when the pits were dug (in April) they filled much higher than that. The geotech identified this to be seeps rushing into the new hole. This water filled in the holes up to about 12" below grade in the worst areas. I assume we couldn't fully determine the extent and occurrence period of these seeps without extensive well monitoring. Would it be reasonable to assume that subgrade compaction will be extremely difficult, and plan on bridging the area with a generous layer of self-compacting material?


I have this question in for the geotech's review, but I could use some preliminary input.

Thanks, much!

 

[Ron]

Your soil characterizations are not consistent with the unified soil classification system....please provide such so that all will know your soil classification.

Using an infiltration test to characterize the structural properties of a soil is not a good idea...wait for the boring data.

"Self compaction" doesn't exist! Compaction requires effort. Don't shortchange that process.

Your comments indicate little soils experience (which is not an issue, just an observation), so there are several things you need to understand about basic soil mechanics before you embark on such an undertaking.

 

[Drumchaser]

I agree with Ron.

It appears this bldg./p-lot site will require costly items of work in order to suspend above the quagmire.