Field Vane in Very Stiff Soils

[BigH]

What is the "maximum" Su value that one would try a field vane? I've just seen a spec that requires the foundation to have an Su value of 150 kPa and says that the field vane is the "preferred" choice. To me, that material is way too stiff for normal commercial field vanes . . . Any thoughts?

Hope you all had a grand celebration of the Chinese New Year! We are now in the year of the Dragon (Water) - my year!

 

[moe333]

ASTM states the vane is valid up to 2 TSF. I worked on a project recently where the drilling company used their smallest vane which maxed out at about 1.5 tsf - no shear. I suppose there are smaller vanes that could go up to 2 TSF but our driller didn't have one. Not sure how common the smaller vanes are. Most are meant for soft soil.

 

[BigHarvey]

Most field vane devices can't go over 100 kPa. At least the ones I know !

 

[BigHarvey]

Geonor H60 can measure up to 200 KN !!

http://www.geonor.com/field_vane_testing.html

 

[emmgjld]

Need a Big Guy to twist it!! Who's up to it??

 

[BigH]

@emmgjld - might need a big guy to push it in too!

 

[BigH]

@BigHarvey - thanks for the link.

 

[BigHarvey]

I'd be glad to try but you might be better off using a 25 kn static penetrometer for the push !

 

[Ron]

A CME 45 and a casing hammer would do nicely!

 

[BigH]

@Ron - and THAT would make the insertion undisturbed? I'd prefer a CME 55 myself . . .

 

[Ron]

Hey BigH...driller's approach when no one's looking....he figures the 45 will disturb less than the 55!

Actually either probably has enough hydraulic push capacity to insert the vane.