Molecules of such water are firmly connected with clay particles, t. e. Strictly oriented. Some researchers call this water hygroscopic. The soil containing only it is always an air-dry.
The amount of hygroscopic water is the value of the variable determined by the ratio of the weight of the water removed from the sample of air-dry soil with drifting at 100-105 ° C to constant weight, to the weight of air-dry soil. For example, for montmorillinite clay, the value of hygroscopic humidity is in the range of 7h-14%, for hydrospital-2h-3%, for kaolinite-14-1.5%.
Loosened (weakly) tied water. Her dipole molecules are focused on. It is also called diffuse water, as it makes up a diffuse layer in a particle.
Firmly connected water moves in pores of soils in the form of steam. Located tied water moves from places where the thickness of the shell is large, to places where it is even larger, which occurs until the water molecules are equally attracted to the particles. Physically connected water forms an inextricably linked water shell around the clay particle. In other words, this shell can be considered as deforming along with a particle under the influence of stresses arising under the influence of load. This determines the interaction of clay particles with water surrounding them, or their hydration.
In conditions of natural occurrence, clay soils to a quarter age, apparently, contain only physically tied water, while Quaternary clay soils most often contain free water.
Physically connected water has a number of features: it is held in soils by forces exceeding the acceleration of gravity by tens of thousands of times; does not flow into drainage structures; does not fully take part in dissolution, evaporates more difficult; its density is more than 1; freezing temperature below 0 ° C.
Firmly connected water has a solid body, and a loosened by the properties of bitumen of various viscosity. It will give clay soils the property of plasticity. Layers of dipole of firmly connected water, “being, as it were, very stupid crystalline (solid) films” (p. A. Rebber), can have a greater strength for a gap called superficial strength, which is measured by the force necessary for its gap.
The adsorption layers of high molecular weight compounds have the greatest strength, so it is among them that builders should find substances for soil processing, for example, when immersing piles, in order to increase their bearing capacity.
The shells of physically connected water of a certain thickness, determined by moisture in soils, are able to push the particle and bags in the particles of Montmorillonite to a known limit. This is the essence of their abolishing action.
Physically connected water reacts very sensitively to all kinds of effects. It is enough to move the clay, as the ratio of water types and, as a result, indicators of its strength properties will immediately change in it.
The foregoing is illustrated by the following examples. On one of the construction in Leningrad, an excavator dug a pit in tape clay. The excavator worked at the edge of the pit and over time from its own movements that caused vibration began to quickly plunge into clay, which softened due to violation of the skeleton-frame, t. With. restraints of their structural ties. Then, on the edge of the pit, a cage made of sleepers for an excavator was placed, hoping that it would save the situation, but they saw that when working, the cage, together with the excavator, plunged into clay.
