You can find such a voltage either on the basis of a large production experience that has developed thanks to observation of the already built foundations, or on the basis of experiments with a trial testing of soil at the level of foundation sole (it is desirable to apply a large area of the loaded column). When experiencing the soil, you should not only strive to establish the limit of proportionality and the dependence between sediments and stress with an increase in the load, but also during the test at least twice to unload the column to determine the elastic recoil of the soil. The first unloading should be started with a voltage of 0.5 kg \ cm2, the second — with 1.0 kg \ cm2, since in rare cases the dynamic effect in stresses exceeds 0.5-1.0 kg \ cm ~. Read more about soil tests said in other departments of the reference book.
