DEPENDENCE OF STRAIN-DEFORMED STATE OF FOUNDATIONS AND BASES DURING THEIR RESTORATION ON THE BASIS OF GROUT-INJECTED PILE TECHNOLOGY

Purpose. To obtain the dependences of the stress-strain state (SSS) of foundations and bases during their restoration on the basis of grout-injected piles for further analysis of the influence of the location of reinforcement elements. Methodology. To determine the SSS parameters and to obtain its dependencies in the foundations and bases during their restoration based on grout-injected piles, a case without reinforcement (option 0) and three options for its reinforcement (Option 1, Option 2 and Option 3) were selected. Reinforcement was carried out with 4 m long soil-cement piles with a diameter of 0.5 m, created on the basis of grout-injected pile technology. Corresponding finite element models have been developed for four options. Their numerical analysis was carried out using a professional licensed SCAD complex. Findings. Contours and isofields of displacements in the models are obtained. The error between analytical calculation and numerical analysis is 3%, which indicates the adequacy of the developed model. The constructed dependences of the stress-strain state of foundations and bases during their restoration based on grout-injected piles indicate that the option that minimizes the level of displacements is Option 1. Analysis of vertical displacements proves that they decrease 2.05 times at the center point of the foundation (option 1), 1.87 times (option 2) and 1.59 times (option 3). Analytical patterns of the stress state show a steady drop in horizontal stresses by 2.77 times (option 1), 1.80 times (option 2) and 1.09 times (option 3) and a steady increase in vertical stresses by 6.20 times (option 1), 4.06 times (option 2) and 1.38 times (option 3). Originality. It lays in obtaining the dependencies of restoring the structures of foundations and bases based on grout-injected piles based on the numerical analysis of the stress-strain state of the “foundation-base” system. Practical value. It consists of the substantiation of the change in the stress-strain state with a variation in the location of the restoration elements created on the basis of grout-injected piles technology.