Implementation of the Non-Associated Elastoplastic MSDPu Model in FLAC3D and Application for Stress Analysis of Backfilled Stopes

The multiaxial Mises-Schleicher and Drucker-Prager unified (MSDPu) criterion has been shown to exhibit several specific features compared other yield failure criteria, including a nonlinear mean stress dependency, influence of the Lode angle, use independent uniaxial compressive tensile strength values absence an apex (singularity) on envelope surface in negative quadrant. However, MSDPu seldom used practice solve geotechnical geomechanical engineering problems mainly because it had not yet fully implemented into three-dimensional (3D) numerical codes. To fill this gap, 3D elastoplastic formulation is developed FLAC3D. proposed elastic-perfectly plastic (EPP) constitutive model then validated against existing analytical solutions for calculating displacement distributions around cylindrical openings. FLAC3D MSDPu-EPP applied evaluate vertical horizontal backfilled stope. results obtained with are those Mohr-Coulomb EPP model, highlight key new formulation.