cphi,
I agree with you to an extent, as I said
"Sometimes moisture/density is very important, and sometimes it is less important" I didn't say not important.
Moisture content in clean granular soils is usually not an issue to obtain compaction unless the moisture is near the bulking...
A lot of things can throw a nuclear gage off, such as atmospheric moisture conditions, or certain elements in the soils. I believe the moisture readings are the most sensitive. Make sure you standardize at least daily, and take trench offsets if you are testing in a trench. If, after doing...
I'd say proofrolling is in-situ testing, albeit a subjective method.
Sometimes moisture/density is very important, and sometimes it is less important. A fat clay compacted at a low water content will not likely fail a proofroll. But I wouldn't want to be the owner of that floor slab come the...
The only program (as of last year) was PRESRED, which is a dinosaur BASIC program from the late '80s. I use it out of necessity, but have also developed a spreadsheet which I use. PRESRED is freeware, I believe, but I couldn't find a download site.
I talked to Dr. Briaud at A&M last year...
We all know that soil properties are variable, so keep that in mind when reading this. Due to the depositional characteristics of loess, the strength properties will vary greatly. The grain size of loess is coarsest near the source. I do a lot of work in the loess hills of Iowa/Nebraska. In...
We have had similar experiences in getting the low spikes at 1-meter intervals where the rods are changed. I'm not sure of your CPT setup, but we have attributed this to equipment deficiencies when pushing in dense/hard soils. Depending on your equipment, this may not be the case.
We use a...
Try checking out https://ssl.blueearth.net/ifai/publications.php3, and go to GFR. GFR (Geotecnhical Fabrics Report) is published 9 times annually, and they come out with a Specifier's Guide in December of each year. The Specifier's Guide has technical information on geogrid, geotextiles...
Try the following link.
http://www.ctre.iastate.edu/research/detail.cfm?projectID=254
CTRE's website has been having some problems lately, but the final report is available as a link of this page, I believe. I tried downloading it yesterday to make sure, but I got an error....trying again...
Certain state DOTs and cities do require calibration testing for SPT equipment. My company has had numerous automatic hammers checked by Goble Rausche Likins (GRL) to meet these requirements. Out of seven rigs from different manufacturers, hammer efficiencies ranged from a little over 50 to a...
I was not aware of the genesis of this method, but, I guess it makes sense that it was pioneered by McClelland in Houston, as I work for both a previous McClelland employee, and someone out of Houston.
It does seem very intuitive, and can work very well. But very good, detailed subsurface...
As everyone else has said here already, modulus of subgrade reaction will vary depending on many things.....including the definition. For instance, I recall one standard method that used modulus values within the upper 10 feet of soils at a site (might be good for pavements, but not mats)...
