Features of the combined impact of driven compaction piles and the associated subsoils

Abstract

The article describes the main features of the combined impact of the driven compaction piles and the associated soil strata. The compaction piles can be pyramidal, machine-driven, or self-expanding when being driven. The peculiarities of the nature of work related to the compaction of the soil strata when the piles are driven. The compaction of the soil strata provides the additional load-bearing capacity and supports the transferred external load. Subsoils and the quantitative assessment of their building properties are evaluated based on the nature and inherent conditions of earth strata formations, and mineralogical and salt compositions. Changes to the fore-said properties depend on the degree of humidity, the peculiarities of soil structure, the location of individual particles, and the resistance to external loads. Internal resistance to compaction is determined by the bulk density of dry soil ρd during the deformation. The abnormalities related to the working of the subsoils associated with driven compaction piles correlate to the transfer of the external load by the lateral surface of the piles to the pre-compacted soil during the course of immersion. In the case of machine-driven batter piles, a compacted soil core between the inner edges of the surfaces of the elements acts in tandem with the pile. In this scenario, the density of the soil composition reaches its maximum value. 
 The results of the field tests proved, that self-opening batter piles perceive 1.2-1.3 times more resistance than pyramidal ones of the same volume. The use of driven compaction piles does not apply to foundations composed of permafrost soils, unstable landslide areas, and to undermined areas.
 The practice of introducing compaction-driven piles into construction has shown significant savings in building materials, and a reduction in the construction time of residential, public, and industrial buildings.