Estimating settlement induced by embankment fill?
Estimating settlement induced by embankment fill?
(OP)
I have a site with the following soil profile:
0 to 30 feet Cemented Hard Pan [SM], SPT N = 100+/ft
30 to 50 feet Very soft clay [CH], SPT N = 2 to 4
There will be a 25 ft embankment fill placed on top of this soil profile for an MSE wall.
I am trying to determine how much stress will be carried by the hard pan (possibly by bridging) and how much will be distributed to the underlying very soft to soft clay.
I need to estimate the amount of settlement that will be induced by the embankment fill.
What would be the best approach to determine this?
0 to 30 feet Cemented Hard Pan [SM], SPT N = 100+/ft
30 to 50 feet Very soft clay [CH], SPT N = 2 to 4
There will be a 25 ft embankment fill placed on top of this soil profile for an MSE wall.
I am trying to determine how much stress will be carried by the hard pan (possibly by bridging) and how much will be distributed to the underlying very soft to soft clay.
I need to estimate the amount of settlement that will be induced by the embankment fill.
What would be the best approach to determine this?





RE: Estimating settlement induced by embankment fill?
RE: Estimating settlement induced by embankment fill?
Check the shear strength of the hardpan. This would be a good application for elastic layer analysis.
RE: Estimating settlement induced by embankment fill?
My quick calculation shows between about 5 to 7 inches of settlement for worst case soil profile. You may monitor the Fill and when your settlement assymptotes, you may proceed with your wall construction.
RE: Estimating settlement induced by embankment fill?
RE: Estimating settlement induced by embankment fill?
RE: Estimating settlement induced by embankment fill?
RE: Estimating settlement induced by embankment fill?
RE: Estimating settlement induced by embankment fill?
RE: Estimating settlement induced by embankment fill?
Thank you for all of your help! Would you be willing to post a copy of your spreadsheet to play around with?
Thanks,
RE: Estimating settlement induced by embankment fill?
RE: Estimating settlement induced by embankment fill?
RE: Estimating settlement induced by embankment fill?
RE: Estimating settlement induced by embankment fill?
The hardpan will act as a raft of some sort, but I'm not sure I'd rely on too much extra attenuation from the hardpan.
Somehow you need to know the maximum past pressure from the clay. Pp-Po may be 1,000 psf, 500 psf or 2,000 psf and that can be a huge factor in the settlement calculation.
You need also to know Cv for the soft clay. I mean if its that thick and the drainage paths are long, the settlement response could take decades.
Run the numbers with Westergaard and Bousinesq. I already know that Westergaard will be less, but it never hurts to bracket your conclusions. . .
f-d
¡papá gordo ain’t no madre flaca!
RE: Estimating settlement induced by embankment fill?
On the other hand, if the clay is really normally consolidated, the differential settlement could be pretty severe when the hardpan cracks.
RE: Estimating settlement induced by embankment fill?
RE: Estimating settlement induced by embankment fill?