Analysis of the stress-strain behavior of compacted rock block layers in shallow foundation

Abstract

In geotechnical engineering, using layers of compacted rock blocks has become a practical alternative for increasing soil bearing capacity, especially for shallow foundations. This study aims to analyze the stress-strain behavior of isolated (rectangular) footings supported on this type of material. For this, the Mohr-Coulomb shear strength parameters obtained through back-analysis (under axisymmetric conditions) of a plate load test performed during a preliminary geotechnical investigation were used. These shear strength parameters were applied in both analytical methods (using the GEO5 software) and three-dimensional numerical modeling (considering the state of three-dimensional stresses and strains) with the RS3 software, employing the Finite Element Method (FEM). The results demonstrated consistency between the approaches and confirmed that the layer of compacted rock blocks significantly enhances bearing capacity, redistributes stress, and reduces settlement. Therefore, this study provides a solid technical basis for adopting this geotechnical solution in shallow foundation projects. The comparison between analytical and numerical methods reinforces the reliability of back-analysis procedures for determining shear strength parameters. Additionally, the results indicate that this type of material can serve as a viable and sustainable alternative to improve foundation performance on low-capacity soils. The study also emphasizes the need for further research under different loading conditions and layer thicknesses to optimize design and deepen understanding of this construction system’s behavior in the field.