I've seen very little about CSSM in typical practice, although about a year ago, I heard Ken Been talk about stability of a massive tailings project in Africa, where they made good use of it. That was an ideal use for it, where they had very large volumes of relatively uniform material...
Gsp-graded soils (lacking grains of certain sizes, therefore having flat portions in their gradation curves) do indeed exist. They can be a real headache for dam foundations and cores.
One caution on the "threshold": If you are getting the threshold N values from the 1997 NCEER report (also published as Youd et al in the 2001 ASCE Journal of Geotech Engrg.) or most other sources, the cyclic resistance on the curve represents about 15% probability of liquefaction, not ~zero...
Interesting question. I suppose at one extreme you would have Mononobe-Okabe (basically Coulomb active pressure with horizontal acc. in addition to gravity). Is that what WALLAP uses? I have never seen MO done with water pressures, and I believe the original derivation was for a nonsaturated...
Just curious - are we talking about direct shear, or direct simple shear? The latter is generally undrained or a pseudo-undrained constant-volume test. I've never heard of a drained DSS test anyway - why would you bother with DS or drained TX being quick and easy, and readily available?
I suppose it could contribute to increased pore pressure initially (like a clay consolidation problem), but within a few seconds to a few months, the pore pressure would match the surrounding area, due to seepage.
Did I understand the question correctly?
MacGruber - Does that last quote refer to the friction angle between fill and wall, rather than internal friction within the soil? The original Rankine model assumed (in effect) that there is no friction on the wall, so the major and minor effective stresses are vertical and horizontal. That's...
It depends on what you are trying to find.
In granular soils, we usually adjust blow count for overburden stress if we are trying to predict relative density or some related property like cyclic resistance ratio because, for a given relative density, the blow count increases with confining...
Sounds like something to avoid unless the client can tell you which ASTM standard to follow (and I don't think there is one). In a typical shear box, I don't think you can shear it fast enough to actually be fully undrained, and how would you know if you had? Maybe if you had a hydraulic...
If you do get it translated into English, make sure that YOU approve the final. I have a book on dam engineering from Spain, with a few glitches in the translation, fortunately minor ones that just sound silly.
For whatever reason, my employer's server forbids me to link to your data, so I can't look at it.
My point was that a strongly dilative material like a dense sand or a clay with OCR>5 causes negative excess pore-water pressure, so the stress path curves off to the right, instead of curving left...
Sounds like either it's strongly dilative, or the sign of the output from the u transducer has gotten flipped. What's the material, and what is its OCR, or relative density, percent compaction, or whatever other parameter might be applicable?
If you haven't already, try the US Army Corps of Engineers Engineering Research and Design Center (formerly Waterways Experiment Station). They have done a lot of research on vehicle mobility on soft ground, and some of it may be unclassified and available.
For most of us practicing geotechs...
Any soil can have both drained and undrained strength. However, for clean gravel and sand, undrained strength is generally irrelevant to anything but a seismic problem.
Yes, limit equilibrium would be the logical thing to do, unless you are also going to have a FLAC or PLAXIS model set up for deformation analysis, in which case you could analyze the stability by "relaxation." You're probably not planning to do that however. You will have to divide the...
