光纤光栅在桥梁预应力索索力监测中的应用

The Application of Fiber Bragg Grating in Bridge Prestressed Cable Force Monitoring

利用光纤光栅传感器长期稳定性好的特点,设计了一种预应力混凝土连续梁桥预应力索索力长期在线的监测方法,研制了一种小尺寸的光纤光栅传感器,印证预应力混凝土连续梁桥跨中下挠和梁体开裂等病害的发生与预应力索索力损失之间的关联。工程应用证明了该传感器及其实施方案的可行性,监测数据表明光纤光栅传感器运行稳定,检测数据可靠,仪表计算机系统建立的索力变化数据库,可为梁体病害的产生和预防起预警指示的作用,为桥梁管养提供科学依据。

For the prestressed concrete continuous beam construction, prestressed cable force long-term effective monitoring is always a challenge for the engineering staff. On account of the good long-term stability characteristics in fiber bragg grating sensor, the article designed a method of the long-term on-line monitoring for prestressed cable force of prestressed concrete continuous beam bridge and developed a small size of the fiber bragg grating sensor, which confirmed the association between the loss of prestressed cable tension and the occurrence of diseases in the prestressed concrete continu- ous beam bridge, such as the more common beam mid-span deflection, beam cracking and so on. The engineering appli- cation demonstrated the feasibility of the sensor and the monitoring program. The monitoring data shows that the FBG sensor is stable and reliable. The computer system created fingerprint database of changes in cable tension. This association plays a role of warning and preventing the appearance of diseases, and provides a scientific foundation for the bridge custody.