A technique for preliminary appraisal of potential and observed scour as applied to state-maintained highway bridges in Maryland

This report describes a technique that can be used to assess potential and observed scour at highway bridges over waterways. Channel-stability assessments were conducted at 876 State highway, U.S. highway, and Interstate highway bridges over waterways in the State of Maryland. Conventional data-collection techniques were used in the field to collect bridge and stream-channel data for each bridge. A potential-scour index and an observed- scour index were developed by assigning numerical-index values to specific diagnostic characteristics of the bridge and stream channel. Potential-scour ratings and observed-scour ratings for assessed bridges were obtained by summing numerical-index values that were assigned to each diagnotic characteristic in the potential-scour index and the observed-scour index.