Growing Market Acceptance for Fiber-Optic Solutions in Civil Structures

Thomas Graver a, Daniele Inaudi b, Justin Doornink c
a Micron Optics, Inc., 1852 Century Place NE, Atlanta, GA, USA 30345
b SMARTEC SA, 6928 Manno, Switzerland
c Bridge Engineering Center, 2901 S. Loop Drive, Suite 3100, Ames, IA, USA 50010

ABSTRACT
Owners must manage and ensure the safety of their civil structures even as use of many structures extends well beyond their design lifetime. Traditionally, most structures rely on strict maintenance procedures, visual inspections, and very few sensors. But maintenance is very expensive, visual inspections can miss critical problems, and conventional sensors can fail in harsh environments. Can fiber-optic sensing (FOS) address these issues? This is not a new question, but there are some new answers. This paper highlights several structures where FOS is used, and describes the associated successes and challenges for each application. Many successes are coupled to improved FOS tools: better sensor packages, simpler and less expensive instrumentation, improved installation techniques, and more efficient data analysis tools. Examples of each are provided. Particular attention is given to the economics of instrumenting civil structures – when and how it pays. Conclusions include recommendations for future developments that will further accelerate FOS acceptance and use.

Keywords: Fiber-optic sensors, civil structures, bridges, fiber Bragg grating, strain sensing

REFERENCES

1 Zhou, Z. et al, “Techniques of Advanced FBG Sensors: Fabrication, Demodulation, Encapsulation, and Their Application in the Structural Health Monitoring of Bridges,” Pacific Science Review, vol. 5, pp.116-121, 2003.
2 Whelan, M., et al., “Overview of Como Cathedral,” http://asa2.jrc.it/, Duomo of Como Database, Joint Research Centre, Ispra, Italy, 2004.
3 Baldwin, C. et al., "Structural monitoring of composite marine piles using multiplexed fiber Bragg grating sensors: Infield applications," Proceedings: Smart Structures and Materials: Smart Systems for Bridges, Structures, and Highways, Vol. 4696, pp. 82-91, March 2002.
4 Mufti, A., ISIS Canda, “Short Course: Structural Health Monitoring and Civionics Systems for Intelligent Civil Infrastructure,” http://www.isiscanada.com/shm_workshop/SHM%20Short%20Course%20Program.pdf, University of Manitoba, 2004.
5 Doornink, J., et al, “ Remote Health Monitoring of a High Performance Steel Bridge Using Fiber Optic Technology,”http://www.ctre.iastate.edu/bec/index.cfm, Iowa State University, 2004.
6 Janoyan, K.D., et al, “Interface Stresses between Soil and Large Diameter Drilled Shaft under Lateral Loading,” ASCE Geotechnical Special Publication No. 124, “Drilled Shafts, Micropiling, Deep Mixing, Remedial Methods, and Specialty Foundation Systems,” 2004.