I'm with you fatdad, but I still have a hard time, in terms of Mohr-Coulomb as described in the post, how a soil experiencing negative suction pressure approaches the undrained strength. Maybe the quote above is simply incorrect. Thoughts??
In researching field conditions that would warrant an undrained total stress analysis, I’ve come across an example that perplexes me. This quote is taken from a technical report (verbatim):
“When the sediments are unloaded, such as occurs when a mine slope face is excavated, the reduction in...
I'm fishing for some advice or a format in creating a "living document". I work for a small firm and typically do 1 and done projects. After the report has been submitted, our work is typically done with the exception of an occasional questions or miscellaneous issue. However, I'm now...
I'm interested in your thoughts on how to locate the position and depth of a tension crack in a method of slices/limiting equilibrium computer analysis. The various programs offer lots of latitude in deciding how/where a tension crack is modeled. I've come across a few schools of thought on...
I don't know the program Abaqus, but I am familiar with finite element analysis. The only FEA software I'm familiar with is FLAC and by no means am I an expert with it.
I think you're better off staying away from finite element analysis for your project. As you mentioned, there are other...
Why are you using Abaqus? There are other methods to evaluating pillar stability. If you want to look at stresses to get an idea of how much the pillars will yield, then this is the right tool. To do this, in addition to the discussed compressive strength and shear strengths, you also need...
This Python stuff sounds really interesting, but climbing the learning curve on another language is an unenvious proposition.
So I ask, what advantages does Python have over my old favs Fortran and Excel VBA?
I'm curious. Why are you posting a geology-related question that seemingly has nothing to do with engineering on a geotechnical-engineering thread? And why do you want to know if the rock could be from France? If you're doing engineering work based on information you get from this sample, you...
Under SKETCH go to PICTURE, click INSERT, select the *.bmp image file and choose some installation base point that doesn't matter for now. Next click SCALE (with your *.bmp file selected under SKETCH, PICTURE). This will allow you to choose 2 scale points (A & B). After you click the 2 scale...
I'm sure we can cut/trim a block out of the saprolite, but what could we do with it?? Sculpting a sample to fit into a triax cell sounds really iffy. Have you ever done this? If there is a good way to do this, then this would be option #1.
As fatdad suggested, I planned to excavate a trench...
Response to your comments geobdg (very good ones)...
I am trying to get an undisturbed sample and diamond coring destroys the soft saprolite, so I'm considering other options. I haven't tried borings and driven Shelby tube samples and wanted to start with considering options for obtaining...
What kind of testing did you have in mind with the block sample and how are the samples prepared from the block?
I also plan to collect a few large-scale direct shear samples (10" square sample) using a custom made metal box carefully driven into the material (have done this before).
My...
This is not academic. In this case, the material at the surface is expected to be continuous for roughly a 20 meter vertical height. The material is a weathered saprolite. In terms of classification, it borders on being hard soild/very soft rock. I'm ultimately hoping to determine a shear...
I'm not a processing guy, but I believe that when coming out of the smelter, the slag is in molten liquid form and is essentially poured onto the slag piles. This is a cool sight to see especially at night. There is no need for slag coming out of the smelter to be crushed.
If you are...
I'm interested in collecting core samples from the surface, without using a drill rig, for triax testing. Details on collecting the sample and extruding it to ultimately get an undisturbed and testworthy sample would be appreciated.
Thanks
There's also the possibility that clay aggregates are contributing to the sand fraction in which case, you have an incorrect sieve analysis and USCS code. I've seen this repeatedly. Look at the sieve material to check.
For very clean fine sand (SP), I've seen direct-shear test results around 27-28 deg for moisture contents from 3-15%.
From what I can put together, it seems that a more well graded distribution of fine to coarse sand with some fines is needed to achieve the interlocking and frictional...
What's your end use? Keep in mind that Q system is specifically designed to determine ground support requirements. If you don't intend to design ground support (ie split sets, cable bolts, lagging, etc.), then don't waste your time with Q.
If you want to determine shear strength for stability...
I would encourage you to stay away from generic published values as it sounds like you have core samples and access to a laboratory. You can do better.
To determine rock C and Phi you can do triaxial testing using a Hoek cell to apply confinement stress. This gets you the "intact" rock shear...
