Comprehensive geophysics investigation of an existing dam foundation: Engineering geophysics research and development, Part 2

Abstract

Part 1 of this paper (TLE, August 1989) reviews recent geotechnical investigations conducted at Beaver Dam, Arkansas. The problem addressed was anomalous seepage beneath Dike 1, adjacent to the main embankment dam. The paper presents a summary of the site geology, seepage history, and foundation grouting programs. Figure 17 is a plan map showing the north and south bounding fault zones of a graben structure beneath Dike 1. The foundation is a down‐faulted block of severely weathered limestone/dolomite of the Boone formation. Figure 4 of part 1 shows a simplified geologic cross‐section through Dike 1 showing the graben structure. Overall objectives of the geotechnical investigations were to assess the anomalous seepage and plan remedial measures to eliminate or significantly abate the seepage. The engineering geophysics investigations discussed in part 1 were designed to detect, map, and monitor anomalous seepage paths and delineate geologic structure beneath Dike 1.