UCS on SPT Samples (thread261-429664)

[studio13]

thread261-429664
I came across the above thread looking for something else and since it wasn't discussed, thought I'd mention it for those interestted. Illinoid DOT (IDOT) here int he US uses what they call a Rimac devise in the field to dp exactly this, perform a UCS of sorts on SPT samples. It's essentially an automitice spring compressor/tester that we test every cohesive sample we collect. There's a correlation to convert to UCS from the measured value and they use it in design of almost everything, driven piles, settlement, seismic site class. They've done research that shows that it's pretty comparable to lab measured values. I was skepticle when I moved here and started doing work for the DOT, but here we are 15 years later still using it on every project.

 

[EireChch]

Very interesting Studio 13, although I would echo the sentiments of the old thread. You must have some stiff CLAYs that suffer lest disturbance when sampled.

Would you have any papers that would show studies on the use of Rimac?

 

[Jimpat]

https://www.rimac-tools.com/

Sample is measured and cut in the field?
SPT is disturbed for sure but maybe better than nothing or even maybe better than STP/N values (depending on the driller/setup).
With the small diameter and disturbance it is probably conservative.
I'd hate to see the calibration data for these in the field with loggers, probably get torn up.

I've seen people run UC on SPT samples before and that was sketchy, but this field measurement with an engine spring tester looks about as accurate as the uncalibrated push pens.