N-value correlation 1

[ehill]

Looking for guidance in evaluating/correlating N-values obtained in 1970 for a 140# hammer with a 24-inch drop and a 140# hammer with a 12-inch drop to SPT N-values. Any suggestions or help would be much appreciated.

 

[jdonville]

ehill,

There was a thread on this topic not too long ago, although it might have been in one of the other geotechnical fora. Do a search and you should come up with it.

Good Luck,

Jeff


Jeffrey T. Donville, PE
TTL Associates, Inc.

http://www.ttlassoc.com

 

[BigH]

Since the hammer size (and presumably the spoon) is the same - normally, the conversion is to take the ratios of energy. For the 12inch drop, multiply "N12" by 12/30. For the 24inch drop, multiply "N24" by 24/30. For different spoon sizes, etc., see chart in Winterkorn and Fang (or now Fang) under the Investigations chapter.

 

[ehill]

thanks for the help everyone, it is much appreciated.