System of selected indicators of tixotropia of clay soils
When testing one monolith, first with a spherical stamp, and then on a single -closed cutting or three -axle device, with a certain size of external pressure, it is possible to build a diagram of maximum stresses during a shift.
A general drawback of the methods of conical and spherical stamps for the study of the kinetics of thixotropy for construction purposes is the impossibility of modeling with their help of those tense states in the soils that will take place in the construction of structures. This is very important, since it is with them that thixotropic hardening proceeds, which, as the studies show, is determined. In connection with the noted, the methods of conical and spherical stamps can be used in most cases only for the qualitative characterization of the possible thixotropic hardening of soils in time in the structure of the structure.
Studies of tixotropic changes in clay soils can also be carried out in stabilometers, odometers and shifts. In them, you can simulate the process of tixotropic hardening by creating an appropriate stress state in the ground, which will take place in the conditions of work. The best devices for determining the strength characteristics of soils are stabilometers that have significantly wider capabilities for modeling real conditions of their operation, since in these devices you can artificially create any ratios between the main stresses and therefore use for the quantitative characteristics of tixotropic hardening in soils.
The main disadvantages of these devices include the fact that each dimension in them is accompanied by the destruction of samples, t. e. A large number of samples are needed to obtain curves of tixotropic hardening.
Above various indicators of clay tixotropia were given. Which of them you need to use? Before answering this question, we recall that thixotropy is a phenomenon consisting of two processes, weighing and strengthening of clay soils.