stroll somewhere in the nature, enjoying the charm of flowering plants, listening to the birds whistling merry songs, you can accidentally be trapped, caught in quicksand.But just be warned that it's not so terrible, as shown in some of the films of the genre "horror".Yes, of course, are best avoided, but at the same time should not be afraid.There are a few consistent rules, knowledge of which is to avoid such situations.
What do quicksand?It really is an interesting natural phenomenon, but not any kind of soil type.A mixture consisting of fine-grained material, clay and water (in deserted places - a mixture of sand and air).It looks solid, but becomes unstable when there is pressure on its surface.She, when the water oversaturates such soil.General, naturally occurring sand (career, mountain, sea) consists of densely packed grains, which form a rigid mass (about 25 to 30 percent of the space between the grains are filled with water or air).Since many of the grains are elongated, their separation can occur, and then the voids will be from 30 to 70 weight percent.This mechanism is similar to a house of cards, where the space between cards is considerably greater than the space occupied by them.Liquid helps create liquefied soil, which is not able to withstand the weight load.
Quicksand can be formed in standing and running waters, the current upward (as in artesian springs).Water jets directed upwards, oppose gravity and inhibit soil particles.Intense rainfall may look solid, but a small strain on their surface initiates liquefaction.This leads to the fact that the sand in the slurry is formed and becomes invalid.Because of amortized water formed quicksand, liquefied sediments, a spongy, like a liquid, soil texture.Objects included in such an environment are lowered to a level at which they are displaced by weight equal to the weight of the mixture (from the soil and water).Liquefaction - a special case of this phenomenon.Thus, in case of an earthquake instantly increased pore pressure in the shallow groundwater.Wet liquefied soil loses its strength, which leads to the collapse of buildings and other facilities located on its surface.
Quicksand are formed where there are natural springs, swampy or wet areas near rivers, beaches, although most of them are not so easy to define.If you suddenly find yourself in them, they recede quickly and smoothly responding with an interval of a few seconds.They are non-Newtonian liquid, that is, in a state of rest are solid (gel form), but the slightest effect on them causes a sharp decrease in viscosity.The deserts are also found, but rarely where there are deposits of sand, for example, on the lee side of the dunes.But the decline is limited to a few centimeters, because as soon as the air in the voids between the grains of sand removed (this occurs quickly), they re-sealed.
