Soil Migration and Piping Susceptibility by the VisCPT

Flow-induced fine soil particle migrations through a skeleton of coarser grains can lead to piping and possible failure of levees and earth dams. It is, therefore, imperative to identify possible soil conditions which are conducive to the piping phenomenon adjacent to water retaining earth structures. This paper presents the results of early research on the use of the Vision Cone Penetrometer (VisCPT) to detect such piping-susceptible soils by literally observing and recording the piping phenomenon as it occurs in-situ. The fine particle migrations occur as a result of excess pore pressures created by CPT advance. Both laboratory and in-situ VisCPT observations are presented showing that the device can detect the fine particle migrations.