DEM simulation of flow property of conditioned sand in EPB tunneling

The feasibility of the discrete element method(DEM) simulation of the flow property of the conditioned soil of earth pressure balance(EPB) is analyzed.The DEM contact model of the conditioned soil is proposed,on the basis of which the slump test of the conditioned soil is simulated by DEM.The standard slump test is improved in the laboratory.The vertical displacement of the marked particles in the simulation accords with the laboratory slump test results and the final slumped shape in the simulation reproduces the laboratory result.The comparision results illustrate that the proposed DEM contact model can simulate the flow property of the conditioned soil,which provide the basis for the further pressure analysis in the closet of the EPB shield machine.