Application of discontinuity layout optimization method to bearing capacity of shallow foundations on rock masses

Abstract

AbstractThe discontinuity layout optimization (DLO) method is applied to obtain the bearing capacity of rock masses where it is necessary to consider a non‐linear resistance law. In rock mechanics, it is widely accepted the modified Hoek & Brown failure criterion, developed for homogeneous and isotropic rock masses. The results obtained with the DLO method are compared with those obtained from the analytical solution and using the finite differences method (FDM). To validate the DLO numerical method, the same hypotheses of the analytical solution are adopted: plane strain conditions, associated flow rule, Hoek & Brown material, and weightless rock. The research analyses the results of a numerical and analytical study based on a sensitivity study varying the three parameters that characterize the rock mass (rock type, uniaxial compressive strength, and geological strength index) and shows the need to adopt an adequate linearization of the non‐linear failure criterion in the numerical calculations. Furthermore, numerical results are obtained considering the self‐weight of the rock mass, using both DLO, considering the intermediate secant linearization proposed in this investigation, and FDM, implemented in a widely accepted geotechnical software. After comparing the results, the advantages and limitations of the DLO method are pointed out.