"Use of Surface-Geophysical Methods to Assess Riverbed Scour at Bridge Piers," In Reply Refer To: June 16, 1989 WGS-Mail Stop 415 OFFICE OF SURFACE WATER TECHNICAL MEMORANDUM NO. 89.10 SUBJECT: PUBLICATIONS--"Use of Surface-Geophysical Methods to Assess Riverbed Scour at Bridge Piers," by S. R. Gorin and F. P. Haeni. The purpose of this memorandum is to announce the availability of the subject report, Water Resources Investigations Report 88-4212. This report discusses the performance and characteristics of four geophysical methods to define existing and previous scour holes around bridge piers. A ground-penetrating-radar system, a black- and-white fathometer, a color fathometer, and a tuned transducer were evaluated for their ability to measure riverbed scour at three bridges in Hartford, Connecticut. Cross sections and some lateral sections were run at each bridge and significant scour at piers supporting the bridges was observed. Each of the four geophysical systems proved to have characteristic advantages and disadvantages. In addition to the discussion of the resulting data from the four systems, there is a table giving a comparative summary. The table includes information on limitations, advantages, costs, technical data, and other information. The report will be very useful to those contemplating using any of these systems for scour determination or similar work. Facilitated by the Office of Surface Water (OSW), this project was funded by the Federal Highway Administration. The results should be of special interest to districts that are or will be involved in bridge-scour projects with state highway departments. A limited number of these reports are available for distribution in the Office of Surface Water. To receive copies, please contact the OSW by electronic mail or by telephone (FTS 959-5301 or 703/648-5301). Ernest F. Hubbard Acting Chief, Office of Surface Water WRD Distribution: A, B, S, FO, PO This memorandum does not supersede any previous OSW Memorandum.