Validity of the Janssen law in narrow granular columns
Department of Physics, University of Oslo, PO Box 1048 Blindern, 0316 Oslo,, Norwegian University of Science and Technology, 7491, Trondheim, Norway
2 Department of Physics, University of Oslo, PO Box 1048 Blindern, 0316, Oslo, Norway
3 Department of Physics, Norwegian University of Science and Technology, 7491, Trondheim, Norway
Published online: 18 October 2005
Abstract.: We have performed experiments on narrow granular columns to test the validity of the Janssen law under such conditions. The weight at the bottom of the cylinder and the compression and movement of the packing have been measured. The apparent mass dependence on height is not in good agreement with the Janssen law using a one-parameter fit. A two-parameter fit yielded good results for the apparent mass during upward and downward movement at constant velocity of the granular column inside the enclosing cylinder. The dependence of the apparent mass on the diameter of the column does not follow the Janssen law. Rather, it depends strongly on details of the packing. A slow force relaxation was observed when stopping the translational stage after upward motion.
Key words: Polymer / Physical Chemistry / Neural Network / Thin Film / Complex System
© EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2005