Pressure regulation for earth pressure balance control on shield tunneling machine by using adaptive robust control

Background: Earth pressure balance shield machines are widely used in underground engineering. To prevent ground deformation even disastrous accidents, the earth pressure in soil chamber must be kept balance to that on excavation face during shield tunneling. Therefore, in this paper an advanced control strategy that a least squares support vector machine model-based predictive control scheme for earth pressure balance is developed. Methods: A prediction model is established to predict the earth pressure in chamber during the tunneling process by means of least squares support vector machine technology. On this basis, an optimization function is given which aims at minimizing the difference between the predicted earth pressure and the desired one. To obtain the optimal control actions, an improved ant colony system algorithm is used as rolling optimization for earth pressure balance control in real time. Results: Based on the field data the simulation experiments are performed. The results demonstrate that the method proposed is very effective to control earth pressure balance, and it has good stability. Conclusion: The screw conveyor speed and advance speed are the major factors affecting the earth pressure in chamber. The excavation face could be controlled balance better by adjusting the screw conveyor speed and advance speed.

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Research on Chamber Earth Pressure of EPB Shield Considering Soil Arching Effect

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1065-1069.373 ◽

2014 ◽

Vol 1065-1069 ◽

pp. 373-377

Author(s):

Jing Cao ◽

Hai Xing Yang ◽

Bo Liang ◽

Hai Ming Liu

Keyword(s):

Earth Pressure ◽

Shield Tunnel ◽

Pressure Balance ◽

Soil Arching ◽

Shield Tunneling ◽

Arching Effect ◽

Soil Arching Effect ◽

Earth Pressure Balance ◽

Tunnel Depth ◽

Epb Shield

Chamber earth pressure is one of the significant parameters during the Earth Pressure Balance (EPB) shield construction processing. The soil arching effect is existence when the tunnel depth is enough. It is significant to consider the influence of arching effect to analyze the pressure in soil chamber in shield tunneling. In this paper, the influence of arching effect is considered to calculate the chamber earth pressure. Firstly, the soil is supposed as loose media, and the necessary buried depth of producing arching affects is deduced according to the loose media theory. Then, based on the characteristic of proper arching axis, the equation and the height of proper arch are obtained. At last, the calculation formula of minimum chamber earth pressure of EPB shield tunnel is deduced which can consider the effect of arching effect.

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Earth pressure balance control for shield tunneling machine based on adaptive dynamic programming

Transactions of the Institute of Measurement and Control ◽

10.1177/0142331220913742 ◽

2020 ◽

Vol 42 (13) ◽

pp. 2440-2449

Author(s):

Xuanyu Liu ◽

Sheng Xu ◽

Kaiju Zhang

Keyword(s):

Cost Function ◽

Balance Control ◽

Earth Pressure ◽

Screw Conveyor ◽

Pressure Balance ◽

The Earth ◽

Gradient Descent Algorithm ◽

Action Network ◽

Earth Pressure Balance ◽

Cutter Head

In order to avoid the safety accidents caused by earth pressure imbalance during shield machine tunneling process, the earth pressure between excavation face and that in chamber must be maintained balance, but it is difficult for practical engineering. Therefore, a data-driven multi-variable optimization method based on dual heuristic programming (DHP) is proposed. First, a cost function with respect to the chamber’s earth pressure is given in light of Bellman’s principle. Then, based on back propagation neural networks (BPNN), the action network, model network and critic network are established that compose the DHP controller. The networks’ weights are updated through the gradient descent algorithm. By minimizing the cost function, the action network utilizes the critic network’s error to optimize the control variables, so that the optimal advance speed, cutter head torque, cutter head speed, total thrust and screw conveyor speed are obtained. Finally, the simulation experiments are carried out, and the results indicate that the method can effectively control the earth pressure balance in chamber and has strong anti-interference ability.

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