The Role of Foam in Improving the Workability of Sand: Insights from DEM

Foam as a soil conditioner can transform the mechanical properties of excavated natural muck and lubricate interface between cutting tools muck, thus reducing tools’ wear promoting efficiency earth pressure balance (EPB) shield tunneling. This paper aims to explore meso-mechanism foam in improving workability sand by combining discrete element modeling (DEM) with experimental investigations slump tests. A “sand-foam” mixture DEM model was generated simplifying grains individual particles different properties. The particle-scale simulated parameters were calibrated based on series observations. effects inter-particle contact distribution evolution forces during slumping process investigated detail through numerical modeling. It found that injecting into specimens could increase coordination number around grains. Although force transmission pattern changes from “sand-sand” coexistence “sand-foam”, “foam-foam” contacts, magnitude transferred is significantly lower than particles. presence reduces contact-scale frictional strength stability microstructures sand. In addition, normal direction deflects vertical horizontal decreases influence foam.