盾构推拼同步技术推进压力开闭环控制方法试验对比

Experimental Comparison of Open & Closed Loop Control Methods for Propulsion Pressure of Shield Pushing & Assembling Synchronous Technology

为解决长大隧道施工周期过长、降低盾构机推拼同步改造与应用难度大等问题,提出一种基于推进系统油压主动控制的推拼同步技术,给出盾构推进过程中因部分油缸回缩造成顶力缺失的总推力控制计算方法,构建大型模型试验平台对压力开环与闭环控制效果进行综合性对比。试验结果表明:压力开环控制下,推进系统油压响应受油缸负载与比例减压阀工作性能的影响较为显著,全过程油压响应并不到位,进行闭环控制后,目标压力执行精度高,误差控制在目标值±4%范围内;进入同步拼装模式后,2种压力控制方式均存在压力响应延迟及推进泵供油过量造成盾构机加速的现象,压力开环控制下总推力的偏差明显大于闭环;设计覆土条件下,压力闭环控制的管片结构抗压安全系数为1.68,明显高于开环,并推荐压力闭环控制方式为盾构推拼同步技术的较优方式。

To solve the problems of too long construction period of long tunnels and reduce the difficulty in the reconstruction and application of pushing & splicing synchronization of shield machines, a pushing & splicing synchronization technology based on the active control of oil pressure in the propulsion system is proposed. The calculation method of total thrust control for the loss of jacking force caused by the retraction of some oil cylinders during the shield tunneling process is given. A large model test platform is built to comprehensively compare the effect of open loop & closed loop pressure control. The test results show that under the pressure open loop control, the oil pressure response of the propulsion system is significantly affected by the cylinder load and the working performance of the proportional reducing valve, and the oil pressure response in the whole process is not in place. After the closed-loop control, the target pressure implementation accuracy is high, and the error is controlled within ± 4% of the target value;after entering the synchronous assembly mode, the shield machine accelerates due to the delay of pressure response and excessive oil supply of the propulsion pump in both pressure control modes, and the deviation of the total thrust under the pressure open-loop control is obviously greater than that under the closed loop control;under the designed earth covering condition, the compression safety factor of segment structure under pressure closed-loop control is 1.68, which is significantly higher than that under open loop control. It is recommended that the pressure closedloop control mode be the preferred mode of shield pushing & splicing synchronous technology.