Detecting the cracks and seepage line associated with an earthquake in an earth dam using the nondestructive testing technologies

Abstract

On 4 March 2010, an earthquake occurred in Chiahsien, Kaohsiung in southern Taiwan that caused cracks in an ancient reservoir. After the earthquake, the depth and distribution of the cracks, and the elevation of the water seepage line had to be detected quickly by the management department (Ministry of Economic Affairs, Taiwan). Accordingly, this research utilized nondestructive testing technologies to examine the reservoir to investigate the damage caused by such a seismic event. The defect detection methods used in this work included ground-penetrating radar and resistivity image profiling. The depth of the cracks was evaluated by ground-penetrating radar and was examined concurrent with the field excavation. Furthermore, the elevation of the water seepage using resistivity image profiling. The data yielded fit the water table evaluation results. Thus, the practicability of the nondestructive detection methods utilized in this research for detecting and evaluating the reservoir after a seismic event was verified.

Keywords:

• reservoir
• cracks
• ground-penetrating radar
• resistivity image profiling

Acknowledgment

The author would like to thank the kind help from the officers in Chia-Nan Irrigation Association, Taiwan and the Ministry of Economic Affairs, Taiwan. In addition, we give special thanks to our colleagues in the Rock Mechanics Laboratory, Department of Civil Engineering, National Cheng Kung University for their assistance during in-situ investigations.