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2 Experiments in Pebble Flows
Fig. 2.6 Pre-filled stripes experiment
approximately be used to get the vertical velocity of the pebble flow, although it is not
recommended. It should be noted that the velocity corresponds to the initial packing
not the final. The velocity between the states of stacking is different. The velocity
of the pebble flow in the lower section is higher than that in the upper section. The
velocity in the center is higher than in the side areas.
The pebble motion is propagated with the tendency from the lower to the upper
section, then from the center to the sides, during which the stacking state of pebbles
will be changed to be different from the initial state. Figure 2.7 shows the initial
packing is in space more compact than the latter. The pebble motion produces a
lot of voids dispersed among the pebble packing with the size from less than one