Wireless Sensing System for Load Testing and Rating of Highway Bridges

Abstract

Structural capacity evaluation of bridges is an increasingly important topic in the effort to deal with the deteriorating infrastructure. Most bridges are evaluated through subjective visual inspection and conservative theoretical rating. Diagnostic load test has been recognized as an effective method to accurately assess the carrying capacity of bridges. Traditional wired sensors and data acquisition (DAQ) systems suffer drawbacks of being labor intensive, high cost, and time consumption in installation and maintenance. For those reasons, very few load tests have been conducted on bridges. This study aims at developing a low-cost wireless bridge load testing & rating system that can be rapidly deployed on bridges for structural evaluation and load rating. Commercially available wireless hardware is integrated with traditional analogue sensors and the appropriate rating software is developed. The wireless DAQ system can work with traditional strain gages, accelerometers as well as other voltage producing sensors. A wireless truck position indicator (WVPI) is developed and used for measuring the truck position during load testing. The software is capable of calculating the theoretical rating factors based on AASHTO Load Resistance Factor Rating (LRFR) codes, and automatically produces the adjustment factor through load testing data. A simplified finite element model was used to calculate deflection & moment distribution factors in order to reduce the amount of instrumentation used in field tests. The system was used to evaluate the structural capacity of Evansville Bridge in Preston County, WV. The results show that the wireless bridge load testing & rating system can effectively be implemented to evaluate the real capacity of bridges with remarkable advantages: low-cost, fast deployment and smaller crew. I would like to express my deepest gratitude and respect for my advisor, Professor Samir Shoukry, for supporting my research and helping me find an area of intellectual pursuit that fit my abilities and interests well. His endless contribution of ideas and insights resulted in bettering my efforts to design the wireless bridge load testing & rating system. Having learned under his tutelage helped me to grow both intellectually and as a person. Many thanks are owed to Dr. Mourad Riad and Dr. Gergis William, who provided me with lots of selfless help and precious experiences in civil engineering and bridges. I would like to thank Professor Michael Palmer for unselfishly sharing with me his encyclopedic knowledge of printed circuit board. My thanks also go to Mr. Hermman Alcazar and Mr. Joseph Greenfeder for helping me with the field tests. I recall the great fun and experience that I gained when working with Mr. Musat Crihalmeanu. Especial thanks to my friend Joe Watring for some of the best experiences of daily life in Morgantown, WV. Lastly, I would like to thank the committee members for this research. Each of you has provided me with your valuable time and precious advices and for that I am indebted to you. iii