In the past decade, Los Alamos National Laboratories has evaluated six non-destructive damage detection algorithms in terms of their ability to detect and locate damage on bridges (Farrar and Jauregui, 1996). While significant at the time, the state of the art has evolved such that damage cannot only be detected and located, it can also be quantified. Although numerous damage detection algorithms exist to detect a change in the structure, that information by itself is of little value to a state bridge engineer. What is needed is a structural health monitoring (SHM) system capable of evaluating the structural capacity and remaining service life of a bridge. Some specific examples of conditions that may impact structural capacity and remaining service life, and for which a SHM system can be used, include the following: ¿ Damage from illegal overweight vehicles ¿ Collision damage (with or without strengthening and repair) ¿ General deterioration of various structural elements ¿ Scour damage from flood events ¿ Damage from extreme events (e.g., seismic, wind)

The ultimate objective of this project is to integrate a damage detection algorithm capable of evaluating a bridge¿s structural capacity and estimating remaining service life into a structural health monitoring system.

The research is proposed to be conducted in three Phases. In Phase I, a gap analysis should be performed to identify areas that require additional work before implementing structural health monitoring as a tool to evaluate structural capacity and remaining service life. Future phases of this project would then be based on the results of the gap analysis, but would address such issues as: ¿ Which damage detection algorithm(s) to implement, ¿ Whether the SHM system should be permanent or mobile, and, most importantly, ¿ How the results from the damage detection algorithm can be utilized to assess capacity and estimate remaining service life. In Phase II, refined algorithms will be developed to determine load ratings utilizing SHM approaches. In Phase III, statistical models will be developed that utilize the load rating algorithms described above to determine structural degradation and remaining service life.

$30,000 -,$50,000 per year for four years requested from particpating states. The project scope is expandable to $1,000,000 depending on the number of states participating.