Theoretical Basis for Forecasting the Expansion of the Diameter of the Leading Well in Water-Saturated Soil with a Crushed Stone Bored Pile

In the process of construction and operation of buildings and structures located on weak water-saturated clay foundations, there is often a need to change their physical and mechanical properties. Currently, various methods of surface and deep compaction are used to improve the characteristics of weak soils. It is known that in the process of deep compaction, the soil is compressed under the action of radial stress on the wall of the leading well using an auger (in reverse motion), pile foundation technology, a rotor, etc. In this paper, the main attention will be paid to solving the axisymmetric problem of consolidation of a soil cylinder under the influence of radial pressure. The diameter of the well in this case increases by 2–3 times and is filled with working material – sand and gravel mixture. The purpose of this study is to carry out a theoretical analysis based on a different approach to solving the problem of the stress-strain state of weak soil during compaction of weak foundations and determining the required characteristics of the compacted composite massif transformed by a bored crushed stone pile. The results of the study convincingly prove that the technology under consideration, based on the expansion of the diameter of the leading borehole in water-saturated soil using crushed stone pile drains, is one of the most cost-effective and efficient solutions. It can compete with traditional compaction methods and the more expensive use of deep foundations.