In each of the video clips below, the VisCPT is advanced in several 5 cm increments.  A short pause between advances allows for observation of soil movement during  excess pore water pressure dissipation.   Such movement occur only in relatively loose cohesionless soils.  Thus, the movements can be related to a soils' susceptibility to liquefaction.

Two types of motion are observed:
   1) Piping of fines through the pore channels of a coarser soil skeleton,
   2) Mass movement of loose relatively uniform soil.

Click on each still image to watch a short video clip
(an ".mpg" file player is needed).

UM26_4-20-s.jpg (43673 bytes)  UM26-1  soil piping - note the stationary coarse particles

UM26_8-40a-s.jpg (42693 bytes)   UM26a-2 soil piping - very dramatic, clearly a loose soil

UM26_8-55a-s.jpg (43077 bytes)  UM26b-1 mass movement - short duration

UM25_6-25-s.jpg (41957 bytes)  UM25-2   mass movement (after last advance only) 

UM25_7-55-s.jpg (43129 bytes)  UM25a-1 mass movement (unusual horizontal flow)

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