In-Situ Stress Measurements and Instrumentation Installation Duke Energy Walters Dam, Waynesville, North Carolina

摘要

This paper serves as a case study for the application of current overcoring stress measurement methods for the structural investigation at an operating United States Federal Energy Regulatory Commission (FERC) dam. Drilling and testing were performed at Walters Dam to characterize the structural effects of concrete growth due to Alkali Aggregate Reaction. The project owner, Duke Energy Carolinas, LLC, engaged HDR, Inc. and Agapito Associates, Inc. to perform drilling and testing on-site for later development of a nonlinear, finite-element model by HDR. In 2016-17. AAI performed concrete and bedrock core drilling, in-situ stress measurements, installed permanent monitoring instruments, and collected baseline instrument readings and concrete samples for lab analysis. Three specialized overcoring stress measurement techniques were utilized: USBM borehole deformation gauge, the CSIRO HI stress cells, and the Sigra, Pty. Ltd. in-situ stress measurement tool. A total of 41 USBM, 6 HI cells, and 28 Sigra measurements were completed. In addition, inclinometer casings, a multi-point extensometer, and downhole temperature sensors were installed.