MDOT Statewide Scour Analysis & Underwater Bridge Inspections

Using multibeam sonar technology, Spicer Group’s hydrographic team collected high-density river bottom topography around the substructure units of major bascule bridges throughout Michigan. As part of the recurring Federal Highway Administration’s underwater bridge inspection requirements, multibeam technology was used in order to capture detailed 3D terrain data on the river bottoms near the bridge piers. The required dive inspections were also performed, however using multibeam sonar, our team was able to capture complete river bottom coverage.

Once processed to survey control, the data was reviewed and compared to the dive inspection results for consistency. In addition, developing scour holes can be accurately measured and analyzed over time. Subsequently, since the data is tied to survey control, it can then be used to develop detailed terrain surface models, cross sections can be extracted from the dataset, and scour countermeasure plans can be developed.