Substructure Completes Bridge Inspection Surveys for Maine Department of Transportation

As part of ongoing bridge assessment work, Substructure employed survey vessel Orion to acquire multibeam data to IHO Special Order standards around bridge structures in the Kennebec and Sheepscot rivers in Maine in June 2009 and July 2010. Substructure’s custom-designed/fabricated 30-degree sonar mount enabled the acquisition of multibeam data up to the water line, while high-resolution, point cloud data-sets around structural supports permitted an assessment of structural integrity and the extent of river bottom scour around the bases of the structures. Performing both baseline and repeat surveys allowed for comparison of initial and current-conditions data. For example, depth-difference comparisons clearly highlighted the erosional and depositional areas around the structure and aided in assessing scour potential. These surveys were conducted for the Maine Department of Transportation as part of their program to periodically inspect all of the state’s underwater bridge structures.

Color hillshade bath...