Rod friction on vane shear test measurements


hello, Would you tell me please how to caluclate the undrained cohesion from in-situ vane shear test when there is a registration of rod friction? and is there any documents , publications or refrences obout this issue? Thanks for your help.
Soil Mechanics / Geotechnical Construction Geotechnical Investigations & In-Situ Testing Equipment
Asked 07/02/2017 12:53, updated: 14/03/2017 10:08
Azaiez Azaiez Dalel

3 Answers

Votes: 0

Jeffrey A Farrar

ASTM D2573 on the Vane Shear Test shows the methods. For rod friction you should use a vane with a slip coupling, or you can use some blank rods tests. ASTM.org and costs $30. I have some other publications if you like...I hlped write the ASTM revisions. Most equipment has the slip couplings and thin low area ratio blades today.

Votes: 0

Azaiez Azaiez Dalel

Thank you very much ; indeed having some references and publications will help me a lot .Would you tell me please about the variation of the rod friction when rotating the vane; does it rise whith the angle of rotation measured or it is constant ?

Votes: 0

Jeffrey A Farrar

I think it's considered a constant. The friction couplers allow the rods above the vane to spin 15 degrees before the vane is engaged. That friction is subtracted from the peak and remolded readings."vane" go to roctest.com and look up the M1000 vane borer...a good mechanical vane.