ABSTRACT
The article presents a new injection technology in the form of an improved design of a drill-injection pile consisting of a hollow metal tube acting as an injector and a controlled broadening at its end, which is formed during grout injection. An algorithm to determine the nonlinear settlement of drill-injection piles in clay soils under static loading is presented. A method to determine the broadening settlement, the pile shaft settlement, with no impact of the controlled broadening at the end of the pile and hydraulic fractures along its shaft, and the total settlement of the drill-injection pile is presented. Diagrams of settlement/load dependence, plotted according to the results of experimental data, calculations according to the proposed methodology and regulatory requirements are shown. A comparison between the values of the pile shaft settlement according to the proposed method and regulatory requirements is carried out and displayed in the form of a diagram. According to the results of numerical calculations carried out using the method presented in this article, it is possible to determine (with a significant margin) the settlement of a drill-injection pile with a controlled broadening at its end. For more accurate determination of the settlement value of a drill-injection pile, it is necessary to take into account residual stresses and changes in mechanical characteristics when forming a compacted soil zone.
