Ground-Penetrating Radar: A Tool for Monitoring Bridge Scour

Abstract

Ground-penetrating radar (GPR) data were acquired across shallow streams and/or drainage ditches at 10 bridge sites in Missouri by maneuvering the antennae across the surface of the water and riverbank from the bridge deck, manually or by boat. The acquired two-dimensional and three-dimensional data sets accurately image the channel bottom, demonstrating that the GPR tool can be used to estimate and/or monitor water depths in shallow fluvial environments. The study results demonstrate that the GPR tool is a safe and effective tool for measuring and/or monitoring scour in proximity to bridges. The technique can be used to safely monitor scour at assigned time intervals during peak flood stages, thereby enabling owners to take preventative action prior to potential failure. The GPR tool can also be used to investigate depositional and erosional patterns over time, thereby elucidating these processes on a local scale. In certain instances, in-filled scour features can also be imaged and mapped. This information may be critically important to those engaged in bridge design. GPR has advantages over other tools commonly employed for monitoring bridge scour (reflection seismic profiling, echo sounding, and electrical conductivity probing). The tool doesn't need to be coupled to the water, can be moved rapidly across (or above) the surface of a stream, and provides an accurate depth-structure model of the channel bottom and subchannel bottom sediments. The GPR profiles can be extended across emerged sand bars or onto the shore.

Department(s)

Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

Bridge Scour; Channel Bottom; Geophysics; Ground-Penetrating Radar (GPR); Multiple Reflections; Bridge Piers; Data Acquisition; Scour; Accuracy Assessment; Echo Sounding; Electrical Conductivity; Flood Frequency; Image Analysis; Monitoring System; Missouri; North America; United States

International Standard Serial Number (ISSN)

1078-7275

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2007 Geological Society of America, All rights reserved.

Publication Date

01 Feb 2007

Link to Full Text

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