Abstract:In view of the disadvantages of traditional force sensors in monitoring the stress of bridge cable, such as inconvenient installation, low test accuracy, brittleness and low ultimate strain of bare fiber grating sensors, a fiber grating intelligent fiber composite sensor (GFRP-OFBGS) was developed to monitor the stress of bridge cable by packaging fiber grating sensors with high durability and high strength glass fiber. Firstly, the processing technology of GFRP-OFBGS and its layout method in bridge cable are given, so that GFRP-OFBGS can co-deform with bridge cable. According to different layout methods, two kinds of self-monitoring intelligent cable, adhesive type and replacement type, are developed. Then, the sensing characteristics of GFRP-OFBGS with different diameters are studied. It is concluded that the strain sensitivity coefficient of bare fiber grating is not changed after it is packaged with FRP, and the temperature sensitivity coefficient is increased by 1.7 times. The ultimate strain increases with the increase of the diameter of GFRP-OFBGS. Secondly, two kinds of self-monitoring intelligent cable are tested respectively. The test results can well characterize the whole tensioning process and tensile force. Finally, the technology of GFRP-OFBG sensor in arch bridge tie rod layout is explored, and it has been implemented and applied in the construction of arch bridge tie rod in Dadu River, Ebian, Sichuan, and the whole tensional process of tie rod has been monitored successfully. Based on the monitoring data of one year, the tensile effect of tie bar is tested and the current operating condition is judged.