About the authors
| First name, Middle name, Last name, Scientific degree, Scientific rank, Current position. Full and brief name of the organization, The organization address. | Hani M. A. Sharaf, Candidate of Engineering Sciences, Senior Lecturer. Kazan State University of Architecture and Engineering, Kazan, Russian Federation E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it |
| Title of the article | Numerical study of the bearing capacity of a composite crushed stone column |
| Abstract. | Problem statement. In weak clay soils, the effectiveness of the improvement technique using crushed stone columns may be limited due to insufficient lateral pressure on the soil. The crushed stone columns should be reinforced by providing the minimum required lateral confining pressure. Plaxis 2D 20 software package was used to verify the numerical analysis. The numerical model was validated based on previous studies and the same material properties and boundary conditions were chosen for the analysis as in the experimental study conducted by A. P. Ambili and S. R. Gandhi [21]. After confirming the validity of the model, four variants of concrete and crushed stone composite stone columns were considered keeping the same material properties and boundary conditions. The aim of the present study is to investigate and evaluate the effect of concrete part on the behavior of concrete-crushed stone composite stone columns compared to conventional crushed stone column. This is accomplished by comparing experimental and numerical results, including the following objectives: 1. To compare the results of the conventional stone column study with the previous experimental study to confirm their consistency and accuracy; 2. To modify the form of the numerical simulation while maintaining all established material properties and boundary conditions. Results: The paper presents the results of numerical investigations of the bearing capacity of concrete and crushed stone composite columns with increasing concrete part within the range of 0.5 to 2.0 stone column diameter. The results showed that the vertical stress increases with increasing the length of the concrete part. The concrete part increases the stiffness of the crushed stone column, which in turn increases its bearing capacity. When the length of the concrete part approached half the length of the crushed stone column, the stress doubled to 2000 kPa at 30 mm settlement. The maximum bulging of the crushed stone column occurs at a depth equal to approximately one stone column diameter, which proves that the horizontal deformation decreases with increasing length of the concrete part of the stone column. Conclusions: The significance of the results obtained for the construction industry lies in the fact that the concept of composite concrete-crushed stone columns successfully combines the advantages of various conventional crushed stone columns. These stone columns have a high bearing capacity superior to that of conventional crushed stone columns, and this is achieved at a competitive price. In addition, composite concrete-crushed stone columns show better bearing capacity compared to bored piles of similar diameter and length. In addition to these advantages, composite concrete-crushed stone columns provide significant resistance to bulging failure. The level of deformation associated with bulging decreases as the length of the concrete portion increases. Also, the stiffness of the concrete-crushed stone composite column increases if the concrete portion is located close to the ground surface. |
| Keywords. | soft soil, settlement, bearing capacity, composite crushed stone column. |
| For citations: | Sharaf H.M. Numerical study of the bearing capacity of a composite crushed stone column // Izvestiya KGASU. 2024. №4(70) P.63-71. |
