Bridge continuous deformation measurement technology based on fiber optic gyro

Abstract

Bridge is an important part of modern transportation systems and deformation is a key index for bridge’s safety evaluation. To achieve the long span bridge curve measurement rapidly and timely and accurately locate the bridge maximum deformation, the continuous deformation measurement system (CDMS) based on inertial platform is presented and validated in this paper. Firstly, based on various bridge deformation measurement methods, the method of deformation measurement based on the fiber optic gyro (FOG) is introduced. Secondly, the basic measurement principle based on FOG is presented and the continuous curve trajectory is derived by the formula. Then the measurement accuracy is analyzed in theory and the relevant factors are presented to ensure the measurement accuracy. Finally, the deformation measurement experiments are conducted on a bridge across the Yangtze River. Experimental results show that the presented deformation measurement method is feasible, practical, and reliable; the system can accurately and quickly locate the maximum deformation and has extensive and broad application prospects.

Keywords

Long span bridge / continuous deformation measurement / FOG / structural safety

References

[1] Jiang D., Sun D., Liang L.. Slab deflection measurement technique based on fiber optic gyro. in Proc. SPIE, 2000, 4077, 141-144.

[2] Spencer B. F.. Opportunities and challenges for smart sensing technology. in First International Conference on Structural Health Monitoring and Intelligent Infrastructure, 2003 65-71.

[3] Ou J., Li H.. Wireless sensor information fusion for structural health monitoring. in Proc. SPIE, 2003, 5099, 356-362.

[4] Jáuregui D. V., White K. R., Woodward C. B., Leitch K. R.. Noncontact photogrammetric measurement of vertical bridge deflection. Journal of Bridge Engineering, 2003, 8(4): 212-222.

[5] Yu Y., Ou J.. Design of wireless intelligent sensor for structural health monitoring. in IEEE Sensor Networks and Information Processing Conference, 2004 1-5.

[6] Nickitopoulou A., Protopsalti K., Stiros S.. Monitoring dynamic and quasi-static deformations of large flexible engineering structures with GPS: accuracy, limitations and promises. Engineering Structures, 2006, 28(10): 1471-1482.

[7] Liu G.. Research about low frequency dynamic characteristics of deflection testing system for LianTongGuan type bridge. Dissertation for the Degree of Master of Chongqing University, 2007

[8] Jang S., Jo H., Cho S., Mechitov K., Rice J. A., Sim S., . Structural health monitoring of a cable-stayed bridge using smart sensor technology: deployment and evaluation. Smart Structures and Systems, 2010, 6(5‒6): 439-459.

[9] Yu Y., Ou J., Li H.. Design, calibration and application of wireless sensors for structural global and local monitoring of civil infrastructures. Smart Structures and Systems, 2010, 6(5): 641-659.

[10] Li S., Hu W., Yang Y., Liu F., Gan W.. Research of FOG-based measurement technique for continuous curve modes of long span bridge. Bridge Construction, 2014, 44(5): 69-74.