What Is Quicksand?
Quicksand is a deep mass of sand so mixed with water that it will not support any weight. It forms when ground water pushes up and mixes into the sand above, making it a thick, soupy liquid.
Watch out for quicksand at the mouths of rivers and along sandy beaches and in marshes.
Since it cannot support weight, a person stepping into quick sand will sink. You can float in quicksand, though, much as you can float in water. You must move slowly, however.
If you struggle, you will simply push yourself in deeper. This makes it seem that you are being sucked down.
There are two ways in which sand can become agitated enough to create quicksand: Vibration tends to enhance the quickness, so that what is reasonably solid initially may become soft and then quick.
The vibration plus the water barrier reduces the friction between the sand particles and causes the sand to behave like a liquid.
To understand quicksand, you have to understand the process of liquefaction. When soil liquefies, as with quicksand, it loses strength and behaves like a viscous liquid rather than a solid. Liquefaction can cause buildings to sink significantly during earthquakes.