Corner-Point Method and Numerical Modelling in Foundation Interaction Analysis

The study presents the results of investigating the impact of a new foundation on the stress-strain state of the soil base and the existing foundation of an adjacent structure. The aim of the research was to compare the efficiency and accuracy of the traditional analytical method—the corner point method—with numerical simulation performed in the LIRA-SAPR software package, which implements elastic-plastic soil model. The obtained results demonstrate that the analytical corner point method enables a rapid assessment of zones prone to additional settlements and the impact on adjacent structures. However, it does not account for the actual stress distribution in a heterogeneous soil mass or the interaction with the stiffness of foundation structures. In contrast, numerical simulation in the LIRA-SAPR software package provides a more detailed analysis of the stress-strain state of the soil, allowing for the consideration of complex geometry and the nonlinear behavior of materials. This is particularly crucial in cases involving challenging soil conditions and the presence of multiple adjacent foundations. The comparison of the results from the two approaches revealed consistency in predicting general trends of settlement and stress changes. However, discrepancies in the absolute values of displacements were observed, reaching 20–30% in some cases. The study results indicate that even in relatively stiff soil with a deformation modulus of E = 28 MPa, the mutual influence of foundations can be significant and requires consideration in design to prevent uneven deformations of the existing structure. The differences between the results of the two methods indicate that relying solely on the analytical approach may lead to an underestimation of the risk of uneven deformations in the existing structure. The study demonstrated that the new flat-plate foundation significantly affects the stress-strain state of the soil and the settlement of the existing foundation. The analytical corner point method allows for a rapid estimation of the approximate level of additional settlements and the zone of influence, but its results are averaged. In contrast, numerical simulation in the LIRA-SAPR software package with the Coulomb-Mohr model accurately reflects the actual stress distribution, local settlement maxima, and plastic soil deformations, thereby improving the precision of the predictions.