Abstract: Due to the complexity and the importance of the stressstrain mechanism in the composite soil nailed wall supporting system, the interaction between the soil nailing and the soil mass is approached from the mesoscale simulations by using the theory of particle flow and it associated discrete element software, PFC2D. The new approach bypasses the macro continuity hypothesis of the traditional continuum mechanics model. The wall deformations of a deep excavation site supported by the soilcement mixed wall and soil nailing are numerically simulated by the discrete element method. The change of the stressstrain, pore water pressure and the micro cracks in the soil mass during the excavation are also numerically monitored. The analytical results are close to the observed values.

Key words: Composite Soil Nailing, Deep Excavation, Discrete Element Method, Mesoscale Simulations