There is the following classification of types of water in the ground:
- crystallized or chemically bound water;
- water vapor;
- hygroscopic water;
- film water;
- capillary water;
- gravitational water.
Let us briefly consider each of the species, as well as methods for removing this water from the soil.
Crystallization or chemically bound water
Crystallization water is part of the crystal lattices of minerals;
It can be removed by calcination and is accompanied by the decay of the mineral.
Water vapor
Water vapor fills the voids of the soil, free of water;
Moves from areas of high pressure to areas of low pressure;
Water vapor condensation contributes to the replenishment of groundwater.
Hygroscopic water
Hygroscopic water is attracted by soil particles from the air and condenses on their surface;
Dried soil in moist air will increase in weight;
It can move in the ground, turning into a vaporous state;
It can only be removed by drying.
Film water
It consists of two phases: tightly bound water (adsorbed) and loose-bound water;
It is held on the surface of soil particles by molecular attraction forces;
They are held on the surface of a soil particle by enormous specific gravity forces of electric attraction;
It does not obey the laws of hydrostatics and hydrodynamics.
Capillary water (waterproofing required)
It rises in the ground along the free tubules formed by mutually communicating pores or is kept in suspension in them.
The height of the rise of capillary water is determined by the meniscus lift, the magnitude of which depends on the wettability of the soil, pore size and water properties
To protect the building structures from capillary water, a waterproofing device is required
Capillary tension force
The average height of capillary rise in soils of natural moisture and normal compaction:
- Loam – more than 1 m (possibly up to 7 m);
- Sandy loam – 0.4-0.6 m;
- Fine sand – 0.3 m;
- Large sand – 0.05 m.
With a pore size of 10-7 cm or less, the formation of capillary menisci is impossible, therefore, the soil becomes waterproof.
Gravity water (waterproofing required)
- Obeys the action of gravity and moves freely in the ground
- Not affected by molecular and meniscus forces
- To protect the building structures from gravitational water, a waterproofing device is required