Field Verification of the Damage Index Method in a Concrete Box-Girder Bridge via Visual Inspection

• Published in: Computer-aided civil and infrastructure engineering 2001-01, Vol.16 (1), p.58-70
• Main Authors: Park, Sooyong, Stubbs, Norris, Bolton, Robert, Choi, Sanghyun, Sikorsky, Charles
• Format: Article
• Language: English
• ISSN: 1093-9687; 1467-8667
• DOI: 10.1111/0885-9507.00213

The structural condition of a concrete box‐girder bridge is monitored twice by detecting and localizing potential damage in the bridge superstructure. Experimental field data were collected on the bridge in December 1997 and 9 months later in September 1998. Modal parameters for the structure are extracted from the measured frequency‐response functions, and the resulting resonant frequencies and modeshapes are fed into a proven systems identification procedure. Modal parameters from the identified baseline structure and the modal parameters determined in the field are used as input to a field‐tested nondestructive damage‐evaluation method (the damage index method) to localize damage in the bridge superstructure. To provide some evidence of the veracity of the predictions of the possible damage locations, a visual inspection was performed on the bridge in May 1999, and surface cracks on the deck were recorded. A comparison of the predicted damage locations on the superstructure with the surface cracks documented via visual inspection is provided. The results indicate that a strong correlation exists between the predicted damage locations and the observed surface crack pattern.