Liquefaction by Waves

During our wave flume model testing in the hydraulics laboratory of NRC Ottawa we were able to establish that saturated sandfills could be brought to liquefaction by purely hydrodynamic influences. As shown in this video the remote passage of a wave train is sufficient, in and of itself, to cause catastrophic failure of the soil-structure. What is mean by "remote" is that the wave form does not make physical contact with the soil-structure.

Of real significance here is that liquefaction can be seen to be triggered in the complete absence of any solid-phase force such as shear waves emanating from earthquake shaking and passing through the ground.

Furthermore, this liquefaction response could only be elicited in loose sands. It could not be elicited in dense sandfills under similar circumstances.

The soil-structure behaviour seen in this video clip is discussed in detail in NRC Video Clip A where Hodge offers his interpretation of the hydrodynamics involved.

It is tempting to attribute this phenomenon to what happens under a tsunami &/or in be ground beneath Rayleigh waves.

But perhaps this is too much of a stretch: Tsunamis and Rayleigh surface waves carry their destructive energy in the first impulse.

Since the wave height involved here builds up progressively from still water, it simply can't be known for sure from our data, if the liquefaction observed here would have resulted from a single wave. What remains unanswered is:

¿ Would a single wave of sufficient height have been enough to have done it ?