Abstract: In view of the lack of the mechanism model lead to can’t to control the pressure of work chamber of shield machine, on the basis of mechanism analyzing of pressure control, the mathematical model of dynamic pressure balance is established. Through the analysis of pressure distribution in work chamber using the discrete element numerical simulation, the effect of cutter opening ratio and tunnel depth to the pressure transitive relation of work chamber is studied, and the mapping between average pressure on bulkhead and the pressure of measurement points is obtained. Pressure transfer coefficient is defined to describe the pressure transitive relation of work chamber, and a procedure of setting the reference value of pressure control based on pressure transfer coefficient is present. Considering the nonlinear and time-varying of mathematical model of pressure control system, a bivariate optimal control strategy of work chamber pressure is proposing. Pressure control simulation experimental results show that the control precision and speed of the proposed control method can realize the requirements of geology adaptability of pressure control.

Key words: dynamic balance, pressure control, transfer coefficient, work chamber of shield machine, Elastohydrodynamic lubrication (EHL), Expansion, Micro oil droplet, Oil-air lubrication