Acoustic Emission Non-Destructive Integrity Assessment of Intermodal Transportation Infrastructure Asset Interactions.

摘要

It is imperative to conduct research and utilize technologies that enhance highway bridge safety by predicting and thus preventing bridge failures. In this work, the technology of acoustic emission (AE) is applied to study the integrity of a highway bridge, the Interstate I-64 bridge crossing over Kempsville Rd in Norfolk, VA. The bridge that comprises the westbound lanes of this crossing utilizes three steel girder spans. One of the girders in the middle span is suspected to carry a defect and the AE monitoring technology is a promising technique in such applications. The AE tests carried out on that girder indicated that the crack is not active and does not pose any threat to the integrity of the structure. The northern span of this bridge has ten steel girders to support the highway. These ten girders are subjected to fatigue loading due to the traffic and it is required to periodically examine their integrity against fatigue cracks. It is expected that the middle girders may undergo heavier load conditions and our measurements did show such a trend. However, the AE measurements also indicated that one girder showed distinctly higher AE activity which was not expected. Thus it is deduced that this girder may have an active crack site, which needs further detailed examinations. It is therefore advised to carry out further NDT tests to check for the integrity of the girder. Visual examinations, dye penetrant tests, and ultrasonic tests can be carried out to locate the source of the defect, if any.