Discrete element model for analysis of chamber pressure of earth pressure balance shield machine

The dynamic working process of the chamber system of shield machine was modeled by discrete element method. Taking the shield machine tunneling in a railway line as the research object, the geometry structure and size of the model was determined. The particle model parameters were calibrated by the triaxial test curves of the soils from the railway ground. Comparing the numerical simulation results of the observed pressure on the chamber board with the field construction data, the validity and the feasibility of the simulation method was testified. Then the mathematical model representing the pressure changing mechanism of the chamber bulkhead was presented, which provided basis for the control of the chamber discharging system.