Bearing capacity of Till Materials
Bearing capacity of Till Materials
(OP)
The excavated test pits in till materials (Vashon Drift - calyey,silty sand and gravel/cobbles/boulders) to a depth of 4 m showed that the ground was hard and with 90 degree excavation wall. The pocket hand penetromer readings on the excavated walls were consistantly over 3.5 tsf. What would be a typical allowable bearing pressure for these materials.





RE: Bearing capacity of Till Materials
Concern #1 - the pocket penetrometer is rather empirical.
Concern #2 - the pocket penetrometer is an attempt to depict the undrained shear strength, which is not meaningful to granular "till" like soils.
Concern #3 - what's below the depth of 12 ft?
Concern #4 - what's with the mixed units, i.e., tsf and meters?
Concern #5 - what's the anticipated column loads?
Concern #6 - what you building?
I could go on, but it's Friday. . .
f-d
¡papá gordo ain't no madre flaca!
RE: Bearing capacity of Till Materials
A raft foundation is planned.
Fattad just curious that where that 5ft criteria is coming from. Thank you.
RE: Bearing capacity of Till Materials
RE: Bearing capacity of Till Materials
to the OP, the only reason I said anything about 5 ft is because you have only depicted the soils in the upper 12 ft or so. No knowing what's below that depth, I figured it'd be correct to limit the seat of settlement to the known interval. Typically the seat of settlement extends 2x the square footing dimension or 4x the strip footing width.
f-d
¡papá gordo ain't no madre flaca!
RE: Bearing capacity of Till Materials
Actually the structure is founded at a depth of 10 ft on a raft foundation. But we know that from local experience that the soil is expeted to be similar until it gets to the bedrook. Therefore for a soil with pocke penetrometer readings of 3.5 to > 4.5 tsf what would be a conservative bearing pressure.
RE: Bearing capacity of Till Materials