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. 075 MPa; 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。

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