Jingyu presents a 3D upper-bound limit analysis method to back-calculate shear-strength parameters from observed or inferred slope failures. The method uses kinematically admissible 3D failure mechanisms and optimises internal energy dissipation to match known collapse states. Case studies demonstrate how back-analysed cohesion and friction differ between 2D and 3D approaches, with 3D typically requiring lower shear strength to mobilise equivalent failure mechanisms.
