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Travis Shoemaker

A Remote Sensing Approach to Upstream Slope Inspection

Department: Civil and Environmental Engineering
Advisor: Dr. Michael McGuire

Embankment dams serve many purposes within the United States, including flood control and drinking water storage. Regardless of a dam’s purpose, failure poses a constant risk to the public that must be managed. Risk mitigation techniques include maintenance procedures, operation methods, and inspection processes. Riprap, or rock fragments, are used on embankment dams to prevent erosion of the dam’s upstream shell, which constrains the dam’s clay core. Together, the riprap, shell, and core work to ensure a stable and impermeable slope. The riprap operates as a heavy mass to withstand the forces of wind, rain, and, most notably, waves. The riprap’s size or weight is the most important design factor in ensuring that the embankment can resist these erosive forces. For the current inspection procedures of riprap, a trained dam inspector compares their own interpretation of the riprap’s condition to that of past years. Specifically, the inspector looks for changes in the riprap’s condition that may hinder the riprap’s ability to protect the slope. This time-intensive process is subjective, as different inspectors make significantly different notes than others. Dr. Michael McGuire and the author developed a remote sensing approach to riprap inspection that could be used to supplement current dam inspection techniques. Remote sensing technologies, such as lidar and photogrammetry, allow for the quick production of 3-D point cloud data of a given region’s surface. Dr. McGuire and the author have found an empirical relationship between the point cloud data and the weight of the rock. This relationship may be used to spot anomalous areas of riprap for further inspection. This could allow dam inspectors to focus more closely on potential issues, increasing the efficiency and thoroughness of the inspection. This method could increase the effectiveness of limited inspection resources by allowing for a more comprehensive inspection without greatly increasing the cost.

About Travis Shoemaker:
Travis Shoemaker is a junior at Lafayette College, studying civil and environmental engineering. He has been researching the use of remote sensing for monitoring geotechnical assets for the last year and a half. His main research project involves using lidar and photogrammetry technologies for the use in embankment dam inspection.