Abstract:

The advance speed of EPB shield is directly related to the shield tunneling efficiency. However, its influencing factors are complex and difficult to control directly. To study the influencing factors of advance speed and explore the interaction mechanism between advance speed and its influencing factors, theoretical analysis and field measurement results are combined, the relationship among the shield advance speed and screw conveyor rotation speed, screw conveyor torque, thrust force, cutterhead rotation speed, cutterhead torque are analyzed. The results show that: (1) The strength characteristics of stratum determine the difficulty of cutting rock and soil by cutterhead in some degree, thereby determines the advance speed. (2) For rock stratum and clay stratum, screw conveyor rotation speed and torque and cutterhead torque are significantly correlated with shield advance speed. (3) Screw conveyor affects the output rate of muck through the rotation speed, thereby affecting the fullness of soil cabin and the cutting efficiency of cutterhead, and finally affecting shield advance speed. (4) The cutterhead rotation speed generally shows that the higher the stratum strength, the faster the cutterhead rotation speed. (5) With the increase of cutterhead rotation speed, cutterhead torque decreases significantly, and the increase of cutterhead rotation speed is beneficial for reducing the abnormal wear damage of shield cutter. 

Key words: EPB shield, advance speed, thrust force, screw conveyor, cutterhead torque, cutterhead rotation speed