软土地层盾构推力矢量自适应控制技术试验研究

Experimental Study on Thrust Vector Self-Adaptive Control Technology for Shield Tunneling in Soft Soil Strata

为解决软土地层中盾构轴线自适应控制时,基于纠偏转向需求的目标总推力矢量获取困难的问题,提出一种盾构推力矢量自适应控制技术。通过将盾构总推力与掘进速度,总推力水平和垂直合力矩分别与盾构水平和高程方向目标转向角度进行闭环控制,实现非恒定负载条件下盾构总推力矢量的高速自适应生成。通过构建可模拟盾构直线推进的大型试验平台以及全推进油缸单元全控的液压控制系统,验证非恒定负载力、非恒定负载力力矩以及非恒定负载力矢量条件下盾构稳态推进的可行性。试验结果表明:1)盾构总推力有效响应负载力变化,两者差值保持为系统摩阻力,存在因负载力突变盾构降速后再恢复的现象;2)盾构总推力力矩未及时跟进负载力力矩变化的情况下,切口水平姿态偏差值小幅突变后可超调复位;3)盾构总推力矢量实现了与负载力矢量的协同响应,推进速度偏差整体控制在设定值-1~+2 mm/min,盾构切口水平姿态偏差控制在设定值±3 mm。

To solve the challenges in obtaining the target total thrust vector based on the shield posture adjustment requirements during self-adaptive shield axis control in soft soil strata,a shield thrust vector self-adaptive control technology is proposed in this study.Through the closed-loop control combining the total thrust with the shield tunneling speed,as well as the horizontal and vertical moments of the total thrust with the target steering angles in the horizontal and vertical directions,respectively,the fast self-adaptive generation of the total thrust vector under non-constant load is realized.Then,a large-scale testing platform which can simulate shield tunneling along a straight line and a hydraulic system allowing independent control of all propulsion cylinder units is developed.The feasibility of steady-state driving of a shield under non-constant load forces,non-constant load force moments,and non-constant load force vectors is verified.The test results show that:the total thrust effectively responded to changing load force,and the difference between them was maintained to be the frictional resistance of the system,and recovery after slowdown of the shield due to sudden changes of load force was observed;the horizontal posture deviation of shield head could be overshoot and reset after a small sudden change in the event that the total thrust moments of the shield failed to follow up with the changes of the load force moments in time;the total thrust vectors achieved high-quality collaborative response to the load force vectors,with the tunneling speed and the horizontal posture deviation of shield head controlled in the ranges of-1-+2 mm/min and±3 mm from the set values,respectively.