University of North Carolina at Charlotte. Transportation Policy Studies

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This report focused on two potential applications of terrestrial LiDAR scans on highway

bridges: 1) vehicle crossing effects measured by3-D, terrestrial LiDAR scans of highway bridges

measuring clearance distance; and 2) bridge post-blast geometric assessments of ground-based or

vehicle-mounted terrestrial LiDAR scans. Data collected create a 3-D point cloud, which was

determined to be ideal for measuring before-and-after conditions on bridges and large culverts.

To determine the effects of ambient and seasonal temperature variation on clearance

measurements, periodic monitoring was conducted using data from a four-lane bridge on Harris

Boulevard near the UNC Charlotte campus. A simplistic but practical correlation analysis was

performed, again illustrating that operational LiDAR scanning is a viable technique for bridge

clearance measurements.

Terrestrial 3-D LiDAR scanners generate dense point cloud information that can be used

to establish baseline geometric information for structures and to establish critical dimensional

footprints for before and after-event comparisons. For close range blast effects, the pre-blast and

post-blast scans of a bridge were made in order to establish the potential and measure the impact

of construction blasting-induced effects, and in general, measure damages to bridges or large

culverts. The Colony Road bridge in southeast Charlotte was monitored before and after a nearby

construction blasting. Full-scale, three dimensional scans of the bridge conducted before and after

blasting. Critical sections and geometries were compared to ensure that the bridges were safe for

traffic.

US Transportation Collection

DT0S59-09-H-0005