Your right, it's just try and error, and sometimes it's a challenge for lab tech's patience to match such requirements (for example to prepare a sample for direct shear tests). But with your approach (given soil mass and moisture content) I think it should not take more than five trials to find...
"More specifically, though, for critical structures, do you feel direct shear or triaxial tests are necessary to check the CPT correlations, or do you think the CPT plus index tests is adequate for design of such facilities?"
If you get a budget for intensive testing, take it and improve your...
Both the interpretation and the deriving of soil poperties from CPT-data are highly empiriclly based business. I would never give any geotechnical recomendation for buildings as mentioned in your post without getting the soil in my hands and doing some basic testing.
If I know
- the soils which...
According to german jurisdictions ex-(I would prefer to say in-, but I'm not a native speaker) it is neccesarry to keep a distance between the bed of the ex- (in-) filtrations and the maximum groundwater level of minimum 1 m (approx. 3 1/3 ft.) to prevent any possible groundwater contamination...
addition to cvg...
There are even detention and infiltration bassins without any overflow, planned without any doubt about the hydraulic and geotechnical assumptions made for planning...
If you are looking for earth pressure coefficients k (active/passive) you'll find tables and/or diagrams in nearly every geotechnical textbook. I' sure one of the USACE puplication includes this data.
What kind of soil did you try to test?
If sand samples are percolated from the upper side, it is neccessary to flood them from the bottom (with de-aired water) before testing. Therefor we put the sample in a bucket with an overflow above the upper side of the sample.
Clean the hose carefully and...
BigH: your collection of links to helpful e-literature is unbeliveable!
I tried (and I still try) also to derive correlations between cpt-data and soil mechanics parameters, but in my expirience the reliability of the subsequent derived parameters is generally not sufficient. Some of the well...
If fill (also gravel) is compacted behind a retaining wall, additional earth pressure resulting from the compaction shall be considered in geotechnical analysis. Have a look for the respective approaches.
Sometimes I still prefer chart-solutions for first estimations. Chart solution for slope stability analysis
you may find here: http://www.usace.army.mil/publications/eng-manuals/em1110-2-1902/entire.pdf
Be careful with simplified models disregarding the influence of seepage forces, slope...
BigH, thanks for your answer and the link, it's always usefull to have access to a broad range of literature. "Swamp shooting" and "rolling surcharge" was/is also used in Germany and I admited the terms to my private dictionary. But I'm sorry your proposal does not match the procedure I tried to...
