Organic layer beneath spread footing
Organic layer beneath spread footing
(OP)
A soil boring identified an organic layer approximately 2' thick approximately 8' below grade. Bottom of proposed spread footing is approximately 3' below grade. Structure is 2 story residential dwelling. Material above and below this layer is medium density sand. When consulting the Bousssinesq chart, foundation pressures at 8' are approximately 0.03q which seems negligible. Future significant settlement is a concern. Should I be evaluating the allowable bearing capacity of the organic layer base on 0.03q? Any input would be appreciated.





RE: Organic layer beneath spread footing
RE: Organic layer beneath spread footing
RE: Organic layer beneath spread footing
The other option would be to over-excavate and backfill with structural fill to the 3 foot level.
Mike McCann
MMC Engineering
RE: Organic layer beneath spread footing
RE: Organic layer beneath spread footing
you will find that soil conditions get worse the deeper you get until you get under that layer, either during geotech exploration or construction.
RE: Organic layer beneath spread footing
Mike Lambert
RE: Organic layer beneath spread footing
RE: Organic layer beneath spread footing
RE: Organic layer beneath spread footing
Lotsa money, but problem solved...
Mike McCann
MMC Engineering
RE: Organic layer beneath spread footing
Where's the water table?
Is this layer really buried topsoil (e.g., is the overlying material really fill)?
I doubt I'll get further involved, 'cause I built my practice avoiding residential work.
f-d
¡papá gordo ain’t no madre flaca!
RE: Organic layer beneath spread footing
RE: Organic layer beneath spread footing
The helical piers , if used, they can be spaced some to cut down on the number needed. Screw jacks on each also.
RE: Organic layer beneath spread footing
Carry on. . .
f-d
¡papá gordo ain’t no madre flaca!