A Waterborne Geophysical Technique For Assisting Proposed Dredging Projects

Each year, the U.S. Army Corps of Engineers spends millions of dollars<br>world-wide on river and harbor maintenance and ship channel realignment<br>projects. Currently, the Corps relies on drilling and laboratory testing<br>programs to assess marine sediments in terms of material type, density, and<br>thickness for the purposes of characterizing proposed dredging sites. But<br>sampling and coring programs are costly and provide only discontinuous information<br>about the material characteristics.<br>In 1988, the Corps of Engineers launched a major research and development<br>initiative called the Dredging Research Program (DRP) directed toward<br>developing new or better technologies to improve subbottom sediment characterization,<br>increase dredging efficiency, and reduce the overall costs of dredging<br>and sampling operations. The U.S. Army Engineer Waterways Experiment<br>Station (WES) heads this initiative. Through the combined effort of the<br>Hydraulics Laboratory and Geotechnical Laboratory, the focus of one of its<br>work units is to remotely and efficiently determine the characteristics of<br>subbottom marine sediments using acoustic impedance information together with<br>limited drilling.