Liquefaction:
When the soil is loaded,it would suddenly go firm solid state to liquefied state.
It is likely to occur in loose to moderate granular soil-sols that are able to crumble easily,with poor drainage.
Loose sands, which go from a solid state to have the consistency of a heavy liquid, or reach a liquefied state as a consequence of increasing pore water pressures, and thus decreasing effective stress(pressure), induced by their tendency to decrease in volume when subjected to cyclic undrained loading.
It is often found along riverbeds, beaches, dunes, and areas where windblown silt and sand have accumulated.
this is a video about liquefaction which commonly occur in earthquakes.sorry about the clarity of the video-couldn't get a HD video which is the same as this.Uring the first part of the video if you were to 'strain' your eyes, you actually could see bubbles coming out of the g.round
