PECULIARITIES OF WORK OF DRILL INJECTION PILES IN UNSTABLE WATER-SATURATED SOIL

Abstract

In 2019, work began on the reconstruction of the stadium “Avangard” in Rivne on the basis of the approved project. The first stage of construction was the reconstruction of the stadium's east stand with its expansion and the installation of additional supports for the construction of a canopy over the west stand.

During the reconstruction of the stadium, the drilling and production of injection piles using CFA (Continuous Flight Auger) technology was used. CFA technology is the drilling of pile wells with a continuous auger drill.

The analysis of recent research focuses on the fact that the actual bearing capacity of injection piles is 1.5 - 2.5 times greater than the estimated, which is due to the inclusion in the regulatory documentation of low coefficients of pile conditions to minimize risks at the design stage.

The aim of the work is to develop constructive solutions and tests of borehole injection piles on a specific construction site in unstable water-saturated soil, to compare the calculated bearing capacity of piles with the results of static tests.

For the test, four experimental piles with a trunk diameter of 820 mm were selected, which were sunk into the soil of natural moisture with the immersion of the bottom of the pile on the design mark in the refractory loam.

The results of studies of borehole injection piles with a diameter of 820 mm showed an increase in the bearing capacity of piles by 25% relative to the estimated, while the overconsumption of concrete mix was 26%. The results confirm the established practice of intermediate adjustment of design documentation in terms of individual structural elements of buildings or structures in order to quickly make approved design decisions on the construction site and speed up construction time.