RESULTS OF EXPERIMENTAL TRAY STUDIES OF THE SOIL FOUNDATION BASE REINFORCED WITH MICROPILES

Abstract

Purpose. Obtaining a change in the deformed state of models of unreinforced and reinforced micropile soil base to determine the influence of the reinforcement element. Methodology. The method of research in a flat tray was used, which makes it possible to solve a certain range of tasks related to the interaction of foundations with the soil base. The conditions for conducting experimental research and the features of creating models of unreinforced and micropile reinforced soil bases are given. The conditions for creating clay paste, laying it in a flat tray, preparing the model for loading, and taking measurements are given in detail. To assess the adequacy of experimental tray studies, modeling conditions were calculated based on the parameters of a real civil structure, its foundation and soil base. Findings. During the experimental studies of the soil foundation and its interaction with the base in a flat tray, two series of experiments were conducted, three experiments in each series. In series Nos. 1-3, an unreinforced base was studied, in series Nos. 4-6, a base reinforced with a single micropile. Vertical displacements were averaged, which were measured by three dial indicators installed in the middle and on both sides of the die that modeled the foundation. On the basis of the results obtained during the experimental studies, diagrams were plotted in σ – s coordinates (stress – settlement). Originality. The originality of the work consists of obtaining a change in the deformed state of the models of unreinforced and micropile reinforced soil base and determining the influence of the reinforcement element (the maximum vertical displacement of 14.7 mm in the model reinforced with micropile in contrast to 17.5 mm in the unreinforced one, i.e., the reduction of this component of the deformed state by 1.19 times). Practical value. The practical value of the conducted research lies in the proof of the positive impact of micropiles based on the results of experimental tray studies. Based on the obtained results, it is reasonable to apply micropiles created with the help of drilling-mixing technology to successfully reduce the vertical displacements of the foundations of civil structures on weak soil bases.