148 The University of Delaware’s Center for Innovative Bridge Engi- neering (CIBrE) proposed and was awarded a contract to design and install a long-term structural health monitoring (SHM) system on the bridge during its construction. The new bridge has a minimum 100-year design life, and the inspection and maintenance of the bridge during that time will require a substantial investment in time and resources. By installing the SHM system, Delaware DOT will be able to understand how the as-built bridge is functioning and through long-term monitoring will be in a better position to efficiently and effectively manage this significant resource. The work proposed by CIBrE consisted of the following: • In consultation with Delaware DOT and the design–build team, finalize the design of a robust fiber-optic–based SHM system for the bridge; • Install a variety of fiber-optic sensor systems on the bridge; • Install a fiber-optic interrogator and computer control system on the bridge; • Perform controlled load tests and ambient monitoring of the com- pleted structure to establish baseline values for future comparison; and • Develop and implement a long-term monitoring program. Presented in the paper is a description of the new bridge; overview of the SHM system, including the sensors and computer control system; discussion of the monitoring program; and progress to date. DESCRIPTION OF NEW INDIAN RIVER INLET BRIDGE The total cable-stayed length of the new Indian River Inlet Bridge is 1,750 ft. The main span is 950 ft long with side spans of 400 ft. Four pylons reach elevations of 250 ft. Each pylon has 19 anchored stay cables on the north and south faces, totaling 152 stay cables on the bridge. A rendering of the bridge is shown in Figure 1. The superstructure deck is a cast-in-place edge girder system. Posttensioning runs longitudinally through the deck and the edge girder segments as well as laterally through floor beams. A typical deck cross section is 105 ft wide. OVERVIEW OF MONITORING PROGRAM In proposing a program to monitor the Indian River Inlet Bridge, CIBrE focused on developing a SHM system that will provide infor- mation that can be directly used by Delaware DOT to understand the Delaware’s Indian River Inlet Bridge Comprehensive Plan for Long-Term Structural Monitoring Harry W. Shenton III, Patrick D. Carson, Michael J. Chajes, Dennis O’Shea, and Craig Kursinsky Plagued by a serious scour problem, the existing bridge over the Indian River Inlet in Sussex County, Delaware, will be replaced by a 1,750-ft cable-stayed bridge. The new bridge is being constructed under a design–build contract by the team of Skanska and AECOM. The bridge is due to open in summer 2011. As part of this project, a comprehensive structural monitoring system has been designed and will be installed on the bridge to aid in the long-term maintenance and operation of this significant structure. The concept and the design of the monitoring sys- tem were proposed by the Center for Innovative Bridge Engineering, University of Delaware. The system has been designed with the intent of providing quantitative data on the long-term performance of the bridge, which can be used to augment the traditional inspection program. The all-fiber-optic system will include 119 embedded and surface-mounted sensors that will measure strain in the deck and pylons; accelerations on the deck, pylons, and cables; deck inclination; chloride penetration in the deck; temperature; and wind speed and direction. Slow, gradual trends resulting from thermal effects and environmental factors will be captured by the monitor data, readings taken on the hour, every hour. Bridge response under intense live loads, such as heavy vehicles and high winds, will be recorded as event data. A series of baseline readings and diagnostic tests will be conducted once the bridge is completed and will be used for future comparisons. The paper presents an overview of the monitoring system and the monitoring program, a description of the way the data will be used, and the owner’s perspective. The Delaware Department of Transportation (DOT) has awarded a design–build contract to the team of Skanska Southeast and AECOM for a cable-stayed bridge to be constructed over the Indian River Inlet in Sussex County, Delaware. The bridge will span the Indian River Inlet as part of Delaware State Route 1, which Delaware Department of Transportation officials describe as a critical link along the eastern seaboard of the United States. Construction began in summer 2009 and is expected to be completed by summer 2011. The new bridge will replace a five-span, continuous steel girder structure that was built in 1965. The existing bridge has experienced severe scour around the piers located in the tidal inlet, which is the reason for the new bridge. H. W. Shenton III, P. D. Carson, and M. J. Chajes, Center for Innovative Bridge Engineering, University of Delaware, Newark, DE 19716. D. O’Shea and C. Kursinsky, Delaware Department of Transportation, Dover, DE 19903. Corresponding author: H. W. Shenton III, shenton@udel.edu. Transportation Research Record: Journal of the Transportation Research Board, No. 2201, Transportation Research Board of the National Academies, Washington, D.C., 2010, pp. 148–153. DOI: 10.3141/2201-17