A monitoring strategy for longitudinal settlement of shield tunnel based on the improved conjugate beam method

作者：Shen Sheng; Wu Zhishen^*; Yang Caiqian; Hong Wan; Wan Chunfeng; Wu Gang

来源：China Civil Engineering Journal, 2013, 46(11): 112-121.

• Conjugate beams
• Distributed characteristics
• Distributed strain
• Fiber Bragg Grating Sensors
• Long term monitoring
• Longitudinal settlement
• Settlement monitoring
• Shield tunnel

As a long-term monitoring index, longitudinal settlement, especially uneven settlement, has been effectively used for the structural safety evaluation of shield tunnels in their operational periods. Due to the lack of distributed characteristic, the widely used traditional monitoring method, which is based on manual observations of settlements at some preset uniformly spaced observation points, may not capture the longitudinal uneven settlements randomly occurred in the practical shield tunnels. Consequently, based on the previous improved conjugate beam method (ICBM) for beam deformation monitoring using distributed fiber optic strain sensing technique, the applicability of ICBM in monitoring the distributed settlements in shield tunnels was theoretically proved. Next, based on the ICBM, a monitoring strategy was proposed to monitor the distributed settlements in shield tunnels by combining the quasi-distributed Fiber Bragg Grating sensors with the hydrostatic level measuring system. Finally, a reduced-scale concrete longitudinal model test was carried out to verify the precision of the proposed strategy for distributed settlement monitoring in shield tunnels. Experimental results show that by using the proposed method, the maximum error in the monitored settlement in the shield tunnel model is only 10%.

• 出版日期2013
• 单位东南大学