Bridge Evaluation Through Advanced Noncontact Sensing Techniques

Considering the half million bridges in the US state highway system, bridge maintenance and management is facing significant funding scarcity problems. Noncontact sensing techniques have the capability of covering large areas and are thought to be cost effective methods for bridge inspection. This paper presents several applications of the noncontact bridge inspection technologies including the use of LiDAR and small-format aerial photography (SFAP). An automatic bridge condition evaluation system, LiBE (LiDAR Bridge Evaluation), is developed based on terrestrial LiDAR data. The system has the functions of bridge defect detection and quantification, clearance measurement, and displacement measurement. An image-based bridge deck evaluation system, AMBIS (Automated Management of Bridge Inspection System), provides bridge evaluations based on bridge surface cracks and size of structural joints. AMBIS integrated with either ground-based photography or SFAP, allows bridge deck condition assessment as well providing peripheral information collection, including furniture accounting and environment assessment. These technologies lead to more accurate bridge evaluations than visual inspection. The results generated from these technologies are valuable for bridge maintenance decision making.