Soil can roughly be classified into cohesionless, cohesive, and cemented soil. In this contribution, a discrete element model for the simulation of cohesive soil is presented. It is based on a model for cohesionless material with spherical particles, normal repulsive and frictional contacts, as well as rolling resistance with an elastic limit to compensate the excessive particle rolling. The cohesive behavior is modeled by an additional attractive normal force between particles. The model is not derived from the microscopic origin of cohesion, such as liquid bridges or electrostatic forces. Instead, it is set up in analogy to the macroscopic shear failure characteristics of cohesive soil. It is observed in video inspections of a bulldozer blade operating in cohesive soil that after the cutting takes place the soil recovers more of its initial cohesion in areas of high compression. In areas away from the blade, the material behaves more like cohesionless soil, forming an angle of response. This behavior is reproduced by introducing a memory effect in the simulation. By that, the amount of cohesion is limited by the pressure that the contacting particles have experienced during the simulation. The discrete element model is shown to be scale invariant in the quasi-static regime, i.e. if all length scales of the model are scaled by a constant factor, the results remain unaffected by the scaling. The model is applied to a bulldozer blade pushing cohesive soil. The contact parameters are calibrated by simulated triaxial compression tests. A comparison between simulation and measurement shows good qualitative agreement
