We present a new numerical approach in the framework of Smooth Particle Hydrodynamics (SPH) to solve the zero energy modes and tensile instabilities, without the need for the fine tuning of non-physical artificial parameters. The method uses a combination of stress-points and nodes and includes a new stress-point position updating scheme that also removes the need to implement artificial repulsive forces at the boundary. The model is validated for large deformation geomechanics problems, and is able to simulate strain localisation within soil samples and slopes. In particular, the new model produces stable and accurate results of the failure and post-failure of slopes, consisting of both cohesive and cohesionless materials, for the first time. (C) 2020 The Author(s). Published by Elsevier B.V.