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Information technology issues for the continuous health monitoring of the Commodore Barry Bridge will be presented in two parts in this paper. The first part describes data acquisition design and the second part discusses issues related to a proposed database. Currently, the health monitor consists of more than one hundred channels of information. These channels are made up of slow speed strain gages (measuring intrinsic strains due to environmental effects, temperature changes and wind loads), high-speed strain gages (measuring strains and accelerations related to traffic effects) and one camera (recording images of the traffic pattern at the bridge). These gages are hard-wired to a central data acquisition station in which three slow speed data acquisition systems, one high-speed data acquisition system and a data acquisition computer are located. All data acquisition systems are integrated under the LabVIEW platform. It was necessary to utilize various appropriate sampling frequencies for each system due to the differing nature of the phenomena being measured by each system. The data is post- processed subsequent to acquisition and finally the data is stored and archived. Post-processing algorithms are implemented to eliminate any noise component from the data, complete any necessary signal re-sampling, and to synchronize the collection times of the different data collection systems. Once the data is transferred and archived data analysis can begin. The creation of a database for storage of all pertinent information is envisioned as a future add-on to this project. Two possible versions of the database system are currently being investigated. In the end, the database would allow users to retrieve information according to customized query criteria. It would also allow users to navigate raw data, preview data graphs, extract specified information (such as analytical data, reports, images, video clips and CBB CAD models), save the retrieved data to a local computer hard-disk and modify information for authorized users. One of the system designs being investigated would not be Internet based and thus would provide local users efficient means of access. In this design, the database would perform complex computational work without coming into contact with Internet traffic. The second proposed system design would provide flexible and robust access through the Internet. This system would allow the retrieval of information from the database through a conventional Browser. This database design would provide fast service and the rich display capabilities of highly dynamic web pages and would allow multimedia capabilities.
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