General questions on the overburden correction (Cn) for SPT.
1) For offshore drilling, the weight of the water column should be included in the effective overburden pressure calculated, correct? This isn't deep drilling, we are looking at 20 - 30 feet of water above lakebed materials.
2) In...
I have a structural engineer who has said that murals on floodwalls can cause damage, as the paint creates a seepage barrier and can increase freeze/ thaw damages to the concrete surface.
I have seen several floodwall projects that have extensive murals, but they tend to be in warmer...
I have a project where we will be creating a wetland by filling in an old canal that is currently submerged with up to 10 to 15 feet of free draining fill. In the canal, there is approximately 10' of extremely weak silts (c~40 - 80 psf) before hitting stiff clay. We will likely place a...
I want to make sure I have a good understanding of the term effective stress, and how it impacts short and long term analysis (lets say a sliding analysis).
If you are calculating lateral earth pressures, your vertical stresses will be the same for long term or short term analysis, correct...
The referenced table provides typical shear strength of compacted soils by soil classification.
Footnote 2 states that strength characteristics are for effective strength envelopes.
For cohesive soils, the table provides the following values for CL soils:
CL: cohesion (as compacted): 1800...
I have to do a preliminary levee design for a project, but the borrow source for the clay has not been identified. I have found typical values for undrained shear strengths, but I'm having trouble finding typical drained values. I don't anticipate any issues with stability (relatively short...
Excuse me if this is a daft question, I'm sleep deprived due to wonderful baby boy :)
Looking at the Primary Consolidation equation, (S=CcHc/(1+eo)* log....
Your primary settlement goes down with higher initial void ratios. This seems counter-intuitive to me. What am I missing?
Thanks!
The berms are a max height of 8', and are being used to contain dry river sediment.
The semicompacted reference comes from a US Army Corps of Engineers manual for construction of containment facilities for dredged material. Table 6-9 in Chapter 6 states that semicompacted dikes can be...
The soils are a lean CL, with LL ~34, and PI ~21. Sand content varies, but is typically 16 - 20%.
Slopes are very flat for most of the project (7H:1V), but there are a few stretches of 2H:1V. I need to let the designer know if these need to be flattened. I have seen some references to "semi...
I have a geotechncial investigation report for a berm construction project in which the following is included:
*boring logs w/ blow counts
*index testing
* Unconfined compressive tests on in-situ foundation density
*standard and modified compaction
*hydraulic conductivity tests on in-situ...
All of the equations I have come across for settlement calculations differentiate between cohesive and cohesionless materials.
How do you calculate the settlement of organic silts? (ML/ OLs)? It is all weight of hammer blow count material (lake bottom), and has low cohesive values.
Do you...
I'm trying to negotiate a contract for a drilling job that has continuous sampling for a depth of 20'. Just curious if anyone out there has a rule of thumb for continuous sampling. I typically use 5' spacing, and I don't have a great feel for how much continuous will slow down the process...
I am looking at driving H-piles at a site that has a deep (~150') layer of loose silts before hitting hard pan clay.
I would like to use a pile driving analyzer to verify pile capacity, or at least get blow counts for the end bearing material, but my customer is leary of bringing any impact...
