Research And Application On The Fiber Bragg Grating Intelligent Cable In The Project Of Siyang Bridge

The Siyang bridge of the Grand Canal is single pylon cable-stayed bridge withthe main span of135meters, the auxiliary span of90meters. It has a total of60stayed-cables, half of which are respectively arranged in the main span and side span.This paper conducts the research relying on the process of building the Siyang bridgeof the Grand Canal and is written combined with "application and research on the hotextrusion polyethylene epoxy steel-wire cable and intelligent detection technology ",the project of traffic scientific research of Jiangsu province.When building the Siyang bridge of the Grand Canal, for solving the problems ofmonitoring and detecting the cable tension in the construction and usage of thestayed-cable, a kind of fiber bragg grating（FBG）sensor with high sensitivity andgood corrosion resistance was embedded inside the galvanized steel-wire stayed-cablebased on the traditional structure of the stayed-cable to accomplish the intelligentdetection of the cable tension of the stayed-cable of the bridge.This paper elaborates the major component testing the cable tension—thefundamental of the fiber bragg grating（FBG）sensor, studies and proposes the basicrequirements of the fiber bragg grating（FBG）sensor embedded inside the cable.Around these requirements, the fabrication process of the intelligent cable isinvestigated, by more than2million fatigue tests in several loading conditions, whichproves that the intelligent stayed-cable embedded FBG sensor can satisfy therequirements of fatigue resistance, durability and sensitivity.In the real bridge verification of intelligent cable, the researchers carried outrespectively the tests of the cable tension in the construction phase and the operationalphase. The validation of the cable tension of intelligent cable in the construction phaseis mainly combined with the construction monitoring and the requirements adjustingthe cable, through the comparison between the cable tension measured by intelligentcable and the values of cable tension, and the monitoring goals and results tested bythe traditional methods, which proves the sensitivity, precision and convenience of theintelligent cable in construction phase; during the operational phase after completing the bridge, the researchers obtain the variation range of the cable tension throughmonitoring the cable tension and temperature parameters of the stayed-cable onlineand in real-time, which realizes the evaluation of the health state of the stayed-cable.Through the researches above, the problems of detecting intelligently and timelythe cable tension of stayed-cable，which not only avoids the occurrence of safeaccidents but prevents the waste caused by blind cable replacement, while providesnew technical support for realizing the technology with scientific maintenance andmanagement.