Hello, quicksand layer: When the seepage direction of water is from bottom to top, that is, when the direction of water flow is opposite to the direction of soil gravity, when the hydrodynamic force is equal to the effective gravity of underwater soil, an upward hydrodynamic force will be generated, that is, soil particles will be suspended and lose their stability, which is the quicksand phenomenon. When water flows, quicksand flows with the water, thus forming a quicksand layer. It is not recommended to build high floors.
Hope to adopt!