Investigating Hidden Hazards and Failure Modes in River Defense Structures Using Ground-Penetrating Radar (GPR)
Background
This investigation systematically organizes and evaluates failure cases of river defense structures, categorizing their failure causes and modes to serve as reference data for future geological investigations.
The case study focuses on the Baibufan Levee along the Da’an River in Zhuolan Township, Miaoli County (under the jurisdiction of the Third River Management Branch). In 2013, Typhoon Soulik caused severe structural damage to the levee and its connecting roads. Rebuilding works for the damaged section were completed in 2017.
Technical Features
To compare structural characteristics, geophysical survey lines were laid across both the original and repaired levee sections:
- Multi-Line 2D GPR Surveying: Standard levee investigations in Taiwan typically deploy a single 2D GPR line along the levee crest or front slope, analyzing two-dimensional profiles. To improve detection accuracy, this study selected a zone straddling original and newly repaired sections, deploying multiple closely spaced parallel 2D survey lines.
- Overcoming Limitations: By comparing 2D radar profiles along different axial lines within the same levee section, the study addresses potential limitations and blind spots inherent in traditional single-line 2D GPR inspection.
Application of Results
Through refined line deployment and data analysis, this study advances the practical application of levee inspection technologies in Taiwan, enhancing the overall effectiveness of levee risk assessment and management.