Application of the Modified Mohr-Coulomb Yield Criterion in Seismic Numerical Simulation of Tunnels

Abstract

To solve the classical problem that the Mohr-Coulomb yield criterion overestimates the tensile properties of geotechnical materials, a modified Mohr-Coulomb yield criterion that includes both maximum tensile stress theory and smooth processing was established herein. The modified Mohr-Coulomb constitutive model is developed using the user-defined material subroutine (UMAT) available in finite element software ABAQUS, and the modified Mohr-Coulomb yield criterion is applied to construct a numerical simulation of a shaking table model test. Compared with the measured data from the shaking table test, the accuracies of the classical Mohr-Coulomb yield criterion and the modified Mohr-Coulomb yield criterion are assessed. Compared to the shaking table test, the classical Mohr-Coulomb model has a relatively large average error (-6.98% in peak acceleration values, -8.47% in displacement values, -23.93% in axial forces), while the modified Mohr-Coulomb model has a smaller average error (+2.71% in peak accelerations value, +3.19% in displacements value, +7.56% in axial forces). The results of numerical simulation using the modified Mohr-Coulomb yield criterion are closer to the measured data.