A large percentage of the nation's bridges are classified as structurally deficient or functionally obsolete. Many bridges are classified as such due to the bridge's load rating. However, the vast majority of bridges are not actually tested to determine their load capacity. In general, actually testing a structure to determine the load rating is time consuming and expensive. As a result only a low number of bridges can be tested. A main time consuming portion of the load test is the setup of conventional instrumentation to monitor the status of the bridge under test. Typically strain gages and LVDT (or similar) deflection transducers are used. Instrumentation which would allow rapid load testing of bridges is currently being developed and tested at the Federal Highway Administration. This instrumentation includes wireless data acquisition systems interfaced with clamp-on strain gages, which can be placed at a measurement location in a matter of minutes. Also, the instrumentation includes a remote laser- based deflection measurement system. The combination of the two types of instrumentation, wireless data acquisition and laser-based deflection measurements, has the potential to allow a greater number of structures to be load rated giving a more accurate picture of the health of the nation's bridges.

Date Published: 31 March 1998
PDF: 8 pages
Proc. SPIE 3400, Structural Materials Technology III: An NDT Conference, (31 March 1998); doi: 10.1117/12.300122

Published in SPIE Proceedings Vol. 3400:
Structural Materials Technology III: An NDT Conference
Ronald D. Medlock; David C. Laffrey, Editor(s)