In the opening session of the SHMII conference in Vancouver, Dr. Steve Chase, recently retired from Federal Highway Administration in USA (FHWA) has delivered a eye-opening talk entitled "Why is Intelligent Infrastructure Needed?".
Dr. Chase explained that there are currently 597'000 highway bridges in the US and that about 50'000 of them are currently classified as Load deficient, meaning that they do not correspond to the load that should be allowed on them. All of these "deficient" bridges were declared so on the base of visual inspection and mathematical analysis and only a handful (less than 10) have actually been load rated through a load test.
With the current inspection practice, vulnerability and reliability are not addresses and most damage and deterioration processes cannot be addressed by visual inspection alone. No information on the long-term performance of foundations is collected, since these cannot usually be inspected.
To improve bridge management and safety, more information is therefore needed. Technology is available to complement the current inspection practices, but not widely used since it is unproven and not mandatory.
Intelligent Infrastructures would enhance the ability of detecting unsafe conditions and to quantify the bridge performance in the long term.
To address these issues, FHWA has launched the "Long Term Bridge Performance Program", managed by Hamid Ghasemi. The program is currently evaluating proposals to select the prime contractor.
Thursday, November 15, 2007
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