The effect of vibration on soil compaction has gained a good reputation when consolidating an artificially improved foundation. The studies aimed at analyzing the effect of the deep vibration on the properties of the compacted water-saturated soil have made it possible to establish that vibration can be an effective means of consolidation speeding-up. Vibration contributes to the emergence of additional excess pressures in the pore water; the filtration rate due to the increased pressure gradient increases as well. Consolidation speeding-up (soil compaction by squeezing out the pore water) is quite relevant. It is clear that consolidation speeding-up of foundation water-saturated soil is extremely important in site preparation for reducing site preparation time up to a period of a short summer. The study focuses on the mechanism of deep vibration (longitudinal mechanical waves) having an effect on water-saturated soil consolidation. The mechanism is based on the changed physical state of the medium and takes into account its structure. Two soil models have been proposed. The first one-parameter soil model is called a "sandwich (layercake)". The second two-parameter soil model is called a "loose sandwich". In here, the first model is a special case of the second one. Both parameters have simple physical significance. The study shows that according to the proposed mechanism, the effect of vibration on soil consolidation is reduced to redistribution of the relationship between the stress in soil skeleton and the pore pressure versus the value of "vibration pressure" in such a way that the pore pressure increases, nevertheless, cannot exceed the value of the external static load. The paper also presents the results of numerical calculations.

The search for ways of accelerating the preparation of bases on water-saturated boggy areas is an up-to-date problem and requires further scientific study. The conducted researches made it possible to establish that vibration can be an effective means of accelerating the consolidation of water-saturated soils of the bases. Using theoretical and experimental research, a method for numerical solution of the problem was developed.

No abstract

The article describes a modernized design of a drill-injection pile, which allows to perform the whole complex of works on strengthening the foundations of reconstructed buildings without impact, mechanical and dynamic effects. An algorithm is proposed for calculating the subsidence of drill-injection piles with controlled broadening, as well as its comparison with regulatory solutions and experimental data obtained at a construction site in the city of Tyumen. The forecast is given on the changes in the stress-strain state of the soil mass under the building foundation when determining its subsidence. It is shown that the value of subsidence mainly depends on the calculated resistance of the soil mass modified in the process of setting up the drill-injection pile, both on the lateral surface and under the lower end. The analytical solutions presented in the article allow us to more accurately determine the subsidence value, taking into account the changes in mechanical characteristics of soil and residual stresses during the formation of the compacted zone.