The phase field fracture method has emerged as a compelling physical and computational framework for predicting cracking in solids. Complex fracture phenomena such as crack branching, merging and nucleation from arbitrary sites can be captured on arbitrary geometries and dimensions based on Griffith’s energy balance and the thermodynamics of fracture. However, in the absence of an ad hoc split of the strain energy density into tensile and compressive parts, the energy stored in the solid also increases during compressive stress-strain states and becomes available to act as a driving force for fracture. To prevent this, several strain energy decomposition schemes have been presented, the two most popular ones arguably being those referred to as the volumetric-deviatoric split and the spectral decomposition. While these decompositions prevent damage evolution in compressive stress states, they do not allow defining arbitrary failure surfaces, as it would be required to capture the behaviour of geomaterials, among other material types. To address this shortcoming, we present a new framework for decomposing the phase field fracture driving force and particularise it to the Drucker-Prager criterion [1]. Numerical examples addressing crack nucleation and growth are presented, showcasing the ability of the model to capture dilatancy, friction, and confinement effects in granular materials. REFERENCES [1] Y. Navidtehrani, C. Betegón, and E. Martínez-Pañeda, “A general framework for decomposing the phase field fracture driving force, particularised to a Drucker–Prager failure surface,” Theoretical and Applied Fracture Mechanics, vol. 121, 103555, 2022.