Consolidation characteristics of Marine Clays Florida Gulf Coast
Consolidation characteristics of Marine Clays Florida Gulf Coast
(OP)
I am looking for consolidation data, particularly any preconsolidation history, for marine clay deposits in the Pensacola area. These soils are at a depth of about 100' to 145' below MSL. Any references or actual lab data information would be appreciated.





RE: Consolidation characteristics of Marine Clays Florida Gulf Coast
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RE: Consolidation characteristics of Marine Clays Florida Gulf Coast
RE: Consolidation characteristics of Marine Clays Florida Gulf Coast
Why are you looking for consolidation properties in these soils? (Describe your project and problem - in some detail, please.) Do you have any soil borings (and samples) that can be tested? Have you contacted the local universities (with engineering schools)?
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RE: Consolidation characteristics of Marine Clays Florida Gulf Coast
Elev> +10 to -22' Medium to dense sands SPT 22 to 76 bpf
Elev> -22' to -50' Very soft CH/OH marine clays with WOR to 2 blf consistency
Elev> -50' to -75' Medium to very dense sands 20 to 50/4" Blf
Elev> -75' to -95' Mixture of loose SM to very soft clays with WOR consistency to 4 blf
Elev> -95' to -110' Very Dense sand 50/5" blf
Elev. -110' to -140' Stiff to Very stiff clay SPT 9 to 15 blf. PPQ of 1 to 2 tsf.
Elev -140'+ Dense to very dense sand.
The local geotech did not conduct any laboratory tests on the clay strata and is concerned that extending augercast pile foundation to elevation of about -95' (which is about 15' above the clay zone) will result in excessive settlements. I am asking the client that supplementary borings and laboratory testing be conducted including at least 3 consolidation tests within the deeper clay strata. In the mean time, we wanted to get a feel for likely settlements based on the maximum foundation loading. This is in the coastal area so the minimum foundation bearing depth is -12'. The largest foundation has a load of about 9500 kips. Looking at the load transfer mechanism, the load transmitted to the deeper clay will be in the range of about 2500 psf from the pile group. So we were looking for any current data on the preconsolidation characteristics of this clay that may allow us to estimate settlements and also compare the actual laboratory data to other recorded information. Thanks for your comments.
RE: Consolidation characteristics of Marine Clays Florida Gulf Coast
The principal problem that I observed was the type of drilling technology that was used: hollow stem auger. The SP sands below El. -80 ft MSL (+) were severely disturbed. Those upper sands were damn competent, and while settlement was an issue, we were able to deal with it.
Give me an email address, and I'll be happy to discuss the "characters" involved in your case off this forum. Perhaps I know some of the players -
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RE: Consolidation characteristics of Marine Clays Florida Gulf Coast
E-mail to uday@bhate-eng.com. Thanks.
RE: Consolidation characteristics of Marine Clays Florida Gulf Coast
RE: Consolidation characteristics of Marine Clays Florida Gulf Coast
-60'(below the upper very soft clay layer) or go below the 2nd layer of clay to about -95'. The third layer of clay is at elevation of about -110' to -115'.
RE: Consolidation characteristics of Marine Clays Florida Gulf Coast
Thanks for the information - I guess you can't found lighter foundations in the upper zone.
In Atlantic City, NJ, they found most of the very high rise casinos on Franki-piles (expanded base piles) for very high loadings - if I remember correctly - in excess of 250 tons. You might consider such foundations in the -95ft sand layer. You could possible get away with 20 piles or so. As this is about 100ft in length, it might be, though, at the "limit" of such piling. Contact a piling contractor to get his thoughts.
RE: Consolidation characteristics of Marine Clays Florida Gulf Coast