A 3D ground penetrating radar imaging of the heavy rainfall-induced deformation around a river levee: a case study of Ara River, Saitama, Japan*
Toshiyuki Yokota 1 3 Tomio Inazaki 2 Shunsuke Shinagawa 2 Takumi Ueda 11 National Institute of Advanced Industrial Science and Technology, 1-1-1-C7 Higashi, Tsukuba, Ibaraki 305-8567, Japan.
2 Public Work Research Institute, 1-6, Minamihara, Tsukuba, Ibaraki 305-8516, Japan.
3 Corresponding author. Email: yokota-t@aist.go.jp
Exploration Geophysics 40(1) 49-55 https://doi.org/10.1071/EG08108
Submitted: 29 October 2008 Accepted: 20 December 2008 Published: 27 February 2009
Abstract
This paper describes a three-dimensional ground penetrating radar (GPR) survey carried out around a levee of the Ara River in Saitama, Japan, where deformation of the ground was observed after heavy rainfall associated with the typhoon of September 2007. The high-density 3D GPR survey was conducted as a series of closely adjacent four directional sets of 2D surveys at an area surrounding vertical cracks on the paved road caused by deformations induced by heavy rain. The survey directions of the 2D surveys were 0, 90, 45, and –45 degrees with respect to the paved road and the intervals between lines were less than 0.5 m. The 3D subsurface structure was accurately imaged by the result of data processing using Kirchhoff-type 3D migration. As a result, locations and vertical continuities of the heavy rainfall induced cracks in the paved road were clearly imaged. This will be a great help in considering the generation mechanisms of the cracks. Moreover, the current risk of a secondary disaster was found to be low, as no air-filled cavities were detected by the 3D GPR survey.
Key words: ground penetrating radar, high-density survey, river levee, 3D survey.
Acknowledgments
The authors thank the Arakawa-Joryu River Management Office, the Kanto Regional Development Bureau, the Ministry of Land, Infrastructure, Transport and Tourism for permission to publish their data and for their assistance in data acquisition. The authors thank two anonymous reviewers for the constructive comments on the paper that greatly improved the paper.
Arai, I., Tomizawa, Y., and Goto, S., 2006, Landmine detection by impulse radar using array antenna: Journal of the Society of Instrument and Control Engineers 45, 498–503.
Nakauchi, T., Nozu, T., Suzuki, M., Uesaka, S., and Arai, I., 2005, Development of the real-time radar image processing for a horizontal drilling machine: Geophysical Exploration (BUTSURI-TANSA) 58, 475–490.
Whiting, B. M., McFarland, D. P., and Hackenberger, S., 2001, Three-dimensional GPR study of a prehistoric site in Barbados, West Indies: Journal of Applied Geophysics 47, 217–226.
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* *Part of this paper was presented at the 118th SEGJ Conference, 2008.