Exploration and Sampling Methods for Borrow Areas

Abstract

Source: https://erdc-library.erdc.dren.mil/jspui/Beach restoration as a means for mitigating severe storm damage is a major coastal engineering activity in the US Army Corps of Engineers. The single most important element in beach restoration is the availability of sand on a beachfront that is both suitable from an engineering standpoint and stable. Since local financial participation is now legally required on beach restoration projects, improving the efficiency of preconstruction exploration and design techniques has become exceedingly important in overall project management. This study is the first of a series that will examine the state of the art of the various geotechnical and geological technologies used to foster effective and environmentally sound coastal project designs. The current state of knowledge regarding geological indicators of subaqueous, sand-bearing formations is discussed. Existing technology in terms of geophysical equipment and application techniques for exploration programs to locate suitable borrow sources for beach fill are reviewed. Techniques for planning, design, and conduct of field exploration programs are recommended based on experiences covering 30 or more years. The main elements of program planning and design are trackline survey layout, core site selection, scheduling of events, selection of equipment and personnel, and preparation of a realistic cost estimate. Although presently available exploratory equipment is adequate, and there is considerable geological experience in correlating subaqueous geomorphic features to occurrences of sand, there is considerable room for improvement in both areas through future research that could materially lower unit costs for beach sand exploratory programs. Since there is a long-term need for beach restoration, continued improvement in geophysical hardware (in particular, computer enhancement techniques) should be pursued