Tie-bar extension-force online monitoring by optical fiber Bragg grating strain sensors

In this paper, a tie-bar extension-force online monitoring system in a tie-bar arch bridge is presented. Optical fiber Bragg grating strain sensors are embedded in the tie-bar arch bridge for online monitoring of changes in the state of internal force. The relation between the tie-bar extension force measured by optical fiber Bragg grating strain sensors and the internal state of the tie-bar arch bridge under the actions of loading and temperature are discussed. The results show that the embedded optical fiber Bragg grating strain sensors can display the internal-force state of a tie-bar bridge and are a powerful and sensitive assistant that is convenient for and beneficial to engineers and that provides a great variety of options for avoiding disasters.