基于光纤光栅传感的盾尾密封泄漏监测试验研究及分析

针对盾构盾尾密封系统容易发生漏水、漏浆等危险的问题,将光纤光栅压力监测系统布设于盾尾尾刷密封性能试验台,对油脂腔进行多点连续压力测量,并在油脂腔不同压力等级条件下采用人为打开球阀泄放的方式模拟实际工况产生的泄漏。试验表明: 1)当油脂腔某点发生泄漏时,整个油脂腔圆周方向上同时产生缓慢压降,缓慢压降时间最长可达6 min,最大压降可达0. 075MPa; 2)基于光纤光栅传感的盾尾油脂腔多点连续压力监测能够较为准确地监测油脂腔在泄漏试验过程中所发生的压力变化。该监测方法为盾尾密封系统泄漏预警提供可行的解决方案。

Experimental Study and Analysis of Leakage Monitoring of ShieldTail Sealing System Based on Fiber Bragg Grating Sensor

As the water and slurry leakage in shield tail sealing system is of great danger, the shield tail sealing qualitytest is carried out. The fiber Bragg grating (FBG) pressure monitoring system is set up on the sealing performance testplatform of tail brush to continuously measure the pressure of grease cavity at multiple points. The leakage caused by theactual working condition is simulated by opening ball valve of grease cavity under different pressure levels. Theexperimental results show that: (1) When a certain point of the grease cavity leaks, a slow pressure drop occurssimultaneously in the circumferential direction of the whole grease cavity; the longest time of pressure drop reaches 6min, and the maximum pressure drop reaches 0. 075 MPa. (2) The pressure variation in the grease cavity during theleakage experiment can be accurately monitored by the system. The monitoring method can provide a feasible solution forthe early warning of leakage of shield tail sealing system.