Research Into Earth Pressure Control Of Epb Shield Tunnelling Machine

Earth Pressure Balance (EPB) shield is the shield of the more commonly used in the construction of a tunnel boring Special Construction Machinery. During the construction process, EPB Shield generally uses the earth pressure control technology to ensure the stability of excavated surface. If the earth closing chamber is lack of pressure, it will cause the front of foundation settlement, the risk of excavation of surface water gushing or collapse will increase. If the pressure is too much, it will cause the issue such as advancing speed decreases or spewing because of the cutter head torque or the thrust increased. So it has a very important significance for control of the earth surface subsidence and improves speed, lower cost of tunneling excavation that sets a reasonable construction pressure and improves earth pressure tank in shield tunnel construction process of stability.Domestic research on earth pressure control technology is not yet mature, Lag type of earth pressure is often used to correct it .Preset the earth pressure value at first, then adjust the earth pressure according to the actual situation. This type of lagging method can't timely adjust control surface subsidence usually. It causes great dangerous to the surrounding buildings on the surface because of the Surface uplift or subsidence. Then the project quality can not achieve the desired goal.In this paper, earth pressure control technology of EPB shield machine was made the research as follows:1. Put forward three kinds of earth pressure balance operating control mode, and lay the foundation for AMESim simulation research through the studies on the three hydraulic system of the Shield simulation experiment platform2. Build three operating control respectively under the mode of earth pressure balance control model with the AMESim simulation software, and use conventional PID control strategy to realize the earth pressure balance control. In AMESim environment simulation research, the simulation results show that the conventional PID control of earth bin to realize pressure balance control requirements, but the conventional PID control algorithm needs a long time, and has less responsive.3. Now, the rise of neural network, can fully approximate any complicated nonlinear relation, learn and adapt anyone which is unknown or uncertain systems, shield earth pressure balance control systems of nonlinear time-varying, such uncertainty. So the application of neural network on earth pressure balance shield machine control can achieve real-time control. Based on the BP neural network's input and output of two four earth pressure balance control model, using neural network for its Matlab7.0 toolbox to model and simulate, and the simulation results obtained satisfactory effect. 4. Build the mathematical model of EPB shield, and get its main parameters of the mathematical relationship based on the model .Test and verify the correctness of mathematical model of EPS shield through industrial large-scale simulation of shield tunneling experiment platform. Provide the relevant reference for China's EPB shield machine's design and tunnel excavation construction.