Distributed sensing technique for bridge monitoring
TIDC Research Thrust: Transportation infrastructure monitoring and assessment for enhanced life.
PI: Tzuyang Yu (UMass Lowell) 
Co-PIs: Susan Faraji (UMass Lowel), Xingwei Wang (UMass Lowell), Zhu Mao (UMass Lowell), Ehsan Ghazanfari (UVM), and Bill Davids (UMaine)
Institutions: University of Massachusetts Lowell (UMass Lowell), the University of Vermont Burlington (UVM), and the University of Maine (UMaine) 
PI Phone: 978-934-2288

Background:

The project is to develop a system-level distributed sensing technique for the long-term monitoring of bridges (e.g., concrete and composite bridges), using fiber optic, video motion, and electromagnetic sensors. Design of a cost-efficient, easy-to-install distributed fiber optic sensing system for monitoring maximum strain/displacement, shift of neutral axis, and creep deformation of bridges is key to understanding the in-situ durability performance of our transportation infrastructure. This project aims to deliver 1) cost-efficient, easy-to-install design and implementation of fiber optic sensors for various bridge components (e.g., girders and piers), 2) integrated interpretation of distributed strains, structural modal frequencies, and radar images for structural health of a bridge system (local and global), and 3) field implementation (new Grist Mill Bridge, Hampden, ME) and development of a database for a composite bridge. 
Bridges are an indispensable component in ground transportation. Advances in materials and structural design have led to the realization of novel bridges such as ultra-high strength concrete bridges and composite bridges. With their prolonged service life and improved capacity expected, it is necessary to develop a data-driven evaluation approach for the field performance of these novel bridges. While incumbent technologies like fiber optic sensors (FOS) and ground penetrating radar (GPR) are commercially available for component-level inspection and monitoring of concrete and composite structures, the lack of understanding on how these technologies complement each other has prevented bridge engineers from making a well-informed decision on choosing a system-level solution. 
In this project, we have instrumented and inspected one composite bridge (the Grist Mill Bridge in Hampden, ME) during Dec. 30~31, 2020 for data collection, in collaboration with AIT Bridges (Brewer, ME) and Maine DOT (Mr. Dale Peabody, PE). 

Objectives:

Two project objectives are identified and listed in the following. 
  • Develop a system-level distributed sensing technique and its design procedure for composite and concrete bridges – A system-level design procedure using low-cost distributed sensors will be developed and implemented by at least one case study (Hampden, ME). More bridges will be identified with further meetings with MaineDOT, MassDOT, and VTrans.  
  • Develop structural health monitoring algorithms based on mechanical and electromagnetic measurements using fiber optic, video motion, and radar sensors – Data-driven health monitoring algorithms of bridges will be developed for crack detection, delamination detection, excessive strain/deformation detection, and excessive creep detection. 

Expected benefits:

It is envisioned that this project will not only close the knowledge gap in the field performance of composite bridges but also improve our understanding on how a defect/damage can be multiphysically detected and understood. A performance database of composite/concrete bridges can improve numerical modeling accuracy and theoretical prediction of the bridges. In addition, the research outcomes from our project tasks can lead to advances in structural ageing and deterioration, essential to the quantitative characterization of transportation infrastructure durability. Development of multiphysical health monitoring algorithms using strain, temperature, dynamic parameters, and electromagnetic measurements of bridges is the basis to monitor structural health of our critical transportation infrastructure.