An Overview of Geophysical and Non-Destructive Methods for Characterization of Roads and Bridges

A variety of remote sensing, surface geophysical, borehole geophysical and other non-destructive methods can be used to determine conditions of roads and bridges. Some of these methods can be utilized to determine subsurface conditions prior to construction. Some can be applied to QC measurements during construction and many can be applied after construction to determine as-built conditions, as well as degradation. The benefit of such measurements are that they are non-destructive, provide in-situ measurements of a wide range of physical properties, sample larger areas or volumes, provide continuous measurements in some cases, and provide faster measurements. All of this results in a greater sample density, which can more readily identify uniform conditions as well as locate anomalous conditions. Once anomalies conditions are identified, those areas requiring further tests, borings or repairs can be accurately and quickly located. These methods can also provide temporal measurements (detecting changes in conditions with time). Such data can be used in a database to guide management decisions for maintenance and repairs. Maintenance and repairs on roads, bridge decks and bridge scour is becoming ever important as our infrastructure ages. A variety of methods can be used to increase the efficiency and technical effectiveness of such inspections. This paper provides an overview of those methods that can and have been applied to characterizing conditions of roads and bridges.