On 11/23/14 60 Minutes drew wide attention to neglect of U.S. infrastructure, correctly attributing this impending crisis to inexcusable dereliction of duty. I won’t claim authority to straighten out our politicians but I can offer a way to light a fire under them: suppose they were given evidence, known also to the public, that collapse of a particular bridge was imminent. Those responsible, to escape subsequent condemnation, would promptly find funds for the essential repairs. The 60 Minutes program showed an instance of exactly that, arising from evidence discovered purely by chance.
OK, maybe that’s obvious, but how could evidence come by design? A year and a half ago I offered a way to approach that, supported by a successful experience analyzing precise daily recordings from monitoring stations surrounding Tohoku (March 2011); both in a Detailed Video Presentation and a short summary are available. For application to infrastructure the details would differ, but certain key features would remain pertinent. Collapse of a steel bridge would be preceded by change in shape of one or more structural members.
The same is true for one made of concrete mixed with polyvinyl alcohol fibers (e.g., used in Japan and New Zealand). Permanent deformation occurs when the elastic limit is exceeded. Gradual accumulation of deformed members would provide early warning. Just as 3-dimensional shape state analysis identified the station nearest a quake epicenter, location of critical structural members would be revealed by a program using sequences of infrastructure measurements.