Abstract This study focuses on a new and high-efficiency approach in a unified sense of accurately simulating strength-degrading effects for geomaterials, including non-symmetric hardening-to-softening effects in tension and compression as well as non-symmetric tensile and compressive stiffness-degrading effects during unloading. It is intended to bypass both modeling and numerical complexities involved in existing approaches. To this goal, new elastoplastic equations are established with new nu