New Approach for Slope Deformation Measurement Using Terrestrial LiDAR in Nuclear Power Plant Site = New Approach for Slope Deformation Measurement Using Terrestrial LiDAR in Nuclear Power Plant Site

다국어 초록 (Multilingual Abstract)

Recently, slope failures are frequently occurred in Korea due to localized torrential rainfalls induced by the world climate change. Therefore, the stability of slopes in nuclear power plant sites has become a major geotechnical issue in the nuclear industry. The slope monitoring using slope-mounted sensors (e.g., inclinometer, tension-wire, and precipitation gauge) are the most accurate and reliable motioning method for slopes. However, slope-mounted sensor systems are ineffective to evaluate the overall deformation of large slopes because measured data from the each slope-mounted sensor represent the single cross-area of the slope. In this study, terrestrial light detection and ranging system (LiDAR) was used to evaluate the overall slope deformation without slope-mounted sensor system. The testbed slope is located in ○○ nuclear power plant site. The length, height, and slope angle of the slope is 1,700 m, 80 m and 34°, respectively. The measurement and analysis procedure are as follows: (1) point cloud data acquisition using terrestrial LiDAR, (2) station adjustment using global navigation satellite system (GNSS), (3) noise filtering to remove unnecessary data (e.g., trees and transmission towers), and (4) slope digital elevation model (DEM) generation. The terrestrial LiDAR data that obtained in 2015 (53 scan positions) and in 2016 (91 scan positions) were compared in this study. There was no significant deformation on the testbed slope, however, slight sediment-scouring which has no impact on the slope stability was observed. Deformation analysis using terrestrial LiDAR data obtained periodically is cost-effective and reliable to monitor the overall deformation of the large slopes.