Geotechnical Core Logging - Solid Core Recovery

[KernowMining]

Over the years, I have been doing numerous core logging exercises. However, I have always wondered what the advantage of collecting the Solid Core Recovery metric is? I know is the percentage of core that is at full core diameter over a set interval, but I, nor many other loggers, have ever used it for analysis. I do remember reading something about it a few years ago, but I can no longer find the reference or remember what it mentioned.

Can anyone shed any light on the uses of Solid Core Recovery (SCR) for Geotechnical design?

 

[fattdad]

if you are talking about RQD it's useful in RMR (rock-mass rating), which in turn relates to kinematics.

If you are dealing with scour, it's useful in evaluating critical shear to initiate scour.

I'm certain this is widely published - google Deere, who developed much of these approaches using RQD.

f-d

ípapß gordo ainÆt no madre flaca!

 

[EireChch]

f-d, hes not talking about RQD. We also report Total Core Recovery (TCR), Solid Core Recovery (SCR), Rock Quality Designation (RQD).

I have only every used RQD.

I would discuss TCR with the driller during a site investigation. If youre getting lower TCR, say around 30%, I would request the driller to do an SPT. If its unquestionable that your in rock then I wouldnt but if youre in material with low UCS (around 0.6MPa, boundary between soil and rock) then doing and SPT may be beneficial as you could be in a dense soil.

 

[KernowMining]

Thanks for the reply all. I know about TCR and RQD. The question was for SCR, which relates the total length of core that is at the full core diameter. I have recently re-optimised my geotechnical logging sheets,and questionsed why so many core logging sheets contain SCR, but I dont know where it gets used!?