Standard penetration test and N values 1

[sundream]

Is there any reference or book that list all the correlations between N (standard penetration number )and poisson's ratio,modulus of elasticity,friction angle?
Thanks

 

[jdonville]

samaryounes,

I believe that Bowles has many tables of empirical relations for these properties. Unfortunately, the Standard Penetration Test is anything but standard in pratice, due to the difference in energy imparted by the apparatus (for many reasons) by different hammers and drill crews. Additionally, hammers have become more efficient since the rope and cathead days, making correlations between historical data and modern investigations problematic.

Jeff


Jeffrey T. Donville, PE
TTL Associates, Inc.

http://www.ttlassoc.com

The views or opinions expressed by me are my own and do not necessarily reflect the views or opinions of my employer.

 

[Dirtguy4587]

Use caution when using any N-based correlations. I recommend using a (N1)60 (ie. correct for effective stress and energy) prior to using any SPT data. I don't have my references with me, but I know there are some correlations similar to Bowles.

 

[Panars]

The USA Federal Highway Administration has a manual on subsurface exploration that includes correlations with soil and rock properties.

The manual is Number FHWA-HI-97-021

Subsurface Exploration Training Course in Geotechnical and Foundation Engineering: Subsurface Investigations - Participants Manual

You can find it here:

http://www.fhwa.dot.gov/engineering/geotech/library_listing.cfm

 

[jdmm]

Dispite what my what has been said above, there is no relationship between poisson's ratio, modulus of elasticity and friction angle. Many times over the course of 40 years have people tried to find relationships. Realistically, the resistance of a penetrometer to penetration is related to the 'strength' of the soil and nothing else. Strength can be determined as 'undrained strength' or 'friction angle for a soil of a specified density at a k0 of bla bla...". Any correlation is indirect. A more dense soil is stronger, for example.

The standard penetration value was intended to be an index value of strength and density. It was never intended to be the ultimate design parameter. Move on to some tests that actually measure strength or density.

jim