光纤传感技术在城市地铁工程监测中的应用

以广州地铁五号线小北站工程为例，介绍光纤传感技术的基本原理及光纤传感监测系统的组成，阐述其在城市地铁工程监测的应用方法和监测成果，通过对温度、混凝土应变规律、钢筋应变计的监测结果分析，表明光纤传感器耐腐蚀，反应灵敏且数据稳定，能够细微地反映出各种变化，在地下工程监测中具有广阔的应用前景，但由于首次将光纤传感器应用在地下工程监测，还存在测点选择不典型、光纤传感器对应变和温度交叉感应、对测点保护不够等不足之处。

Application of Optical Fiber Sensing Technology in Monitoring of Urban Metro Works

The principle of optical fiber sensing technology, the composition of optical fiber sensing system and the application of optical fiber sensing technology in the monitoring of urban Metro works are presented, with the case of Xiaobei station on Line 5 of Guangzhou Metro as an example. The analysis on the temperatures, the concrete strain rules and the monitoring results of the re-bar strain gauges demonstrates that optical fiber sensors are corrosion-resistant, rapid in reaction and stable in data transmission. Furthermore, optical fiber sensors can detect the subtle variations. It is concluded that optical fiber sensing technology will be widely used in the monitoring of underground works in the future. However, it is the first time that optical fiber sensors are used in the monitoring of underground works, some problems, such as improper selection of monitoring points, cross-sensing of the optical fiber sensors to strains and temperatures and insufficient protection of the monitoring points, still exist.