NCHRP IDEA 20-30/IDEA 205 [Active (IDEA)]
MRI Bridge Analysis and Multi-Modal Imaging Using Optimal Multi-Coil Resonant Coupling
| Project Data
||University of Alabama - Birmingham|
This project will develop and test an integrated technology of LiDAR to detect surface damage and optimal radio frequency inductive testing (RFIT) to perform bridge magnetic resonance imaging (MRI) for accurate identification of potential deep sub-surface damage in reinforced concrete (R/C) in bridge structures. Work on Stage 1will involve evaluating/assessing existing surface damage to the connection details of two highway bridges (Soapstone Bridges in Dallas County, Alabama) after LiDAR and visual inspection. To complement these "first-pass" findings, spatiotemporal surface-level damage patterns of the connection details of Alabama DOT-inspected in-service bridges will be gathered from data repositories. This information will be used to ascertain potential sub-surface damage. A series of tests will be performed using three laboratory-designed and constructed R/C girders. Pitting corrosion will be introduced to rebar to allow localized holes to develop, and expanded polystyrene (EPS) foam will be placed at strategic depths within certain girders to introduce simulated defects. The results will be used to model/develop and validate the multi-coil optimal RFIT method. Work in Stage 2 will develop FE damage-based models, using interdependently connected "gap" elements to assemble stiffness matrices of the R/C beams. The impedance data on detected damage, gathered during Stage 1, will be post-processed by simulating the radio wave propagations through graphical interpretation. The results will be used to help develop the damaged-based FE models. The models will be used to analyze sub-surface defects, such as cracks and pitting corrosion. The identified sub-surface damage will be compared to damage identified in the experimentally tested beams. Recommendation will be developed based on data obtained from the FE analyses for prognosis of long-term effects of the evaluated/ analyzed sub-surface damage. A cost-effective and appropriate preservation or retrofit plan will be subsequently developed for the Soapstone Bridges in conjunction with initial bridge ratings (using LiDAR data, visual inspection, and spatiotemporal data of damage patterns from Stage 1). The plan will be presented to the Alabama DOT for possible implementation in the Soapstone Bridges. As part of implementation efforts, two hands-on workshops will be organized for potential end-users. In addition, DOT officials will be encouraged to arrange a “live-bridge” demonstration to potential end-users of the developed technology.