Scour at Bridge Structures and Channel Aggradation and Degradation Field Measurements: State of the Art

摘要

A study on bridge scour and bridge related channel instability field measurements was conducted for the Arizona Department of Transportation (ADOT). The objectives of the research were to review and evaluate procedures and field techniques for measuring scour at bridge structures and for monitoring channel aggradation, degradation, and lateral migration; and to recommend a program to initiate data collection in Arizona. The ultimate goal of the research is to provide data and procedures to identify bridges that may be susceptible to scour and channel instability problems so that adequate countermeasures can be undertaken to avoid and mitigate bridge scour incidents and to collect data on scour and channel instability processes in Arizona so that appropriate design and construction procedures can be developed and used in Arizona. Pilot programs for bridge scour have been recommended. These include the use of ground penetrating radar, buried miniature transmitters, post-flood reconstitutions, and mobile teams. A phased monitoring program for channel aggradation, degradation, and lateral migration has been recommended. Level 1 monitoring uses readily available data from the bridge inspection program to identify bridges that may be experiencing these longer term channel changes.