Muography as a novel complementary technique for geotechnical surveys
- 1Earthquake Research Institute, The University of Tokyo, Tokyo, Japan (olah.laszlo@wigner.hu)
- 2International Muography Research Organization (MUOGRAPHIX), The University of Tokyo, Tokyo, Japan
- 3International Virtual Muography Institute (VMI), Global
- 4Wigner Reseach Centre for Physics, Eötvös Loránd Research Network, Budapest, Hungary
- 5NEC Corporation, Global
- 6Sabo Frontier Foundation, Japan
- 7Graduate School of Informatics, Kansai University, Osaka, Japan
Muography is an imaging technique that can utilize cosmic-ray muons for remote and non destructive exploration of large-sized natural and human-made structures [1]. We applied mobile gaseous-detector-based muography instruments [2] for surveying different human-made structures in Japan:
(1) A buried reinforced concrete pillar (that is a standard pillar along Japanese railways) was installed inside a mound, and muography was blind tested from a three meter deep shaft located three meters away from the pillar [3]. Our muographic surveys revealed the bottom of the pillar at the depth of 80 cm with a spatial resolution of 15 cm within a few days.
(2) Debris dams are applied to prevent the catastrophic impacts of fast debris flows on the landscapes in mountain areas. We muographically measured the density-lengths through different debris dams (e.g., see in Ref. [4]) with a spatial resolution of below 50 cm within 2-4 weeks. The muographic surveys detected a weak zone inside a debris dam of Karasugawa river in consistency with elastic wave tomography survey.
(3) Muographic inspection of the Imashirozuka burial mound was conducted for detecting physical evidences related to a past earthquake [5]. This mound collapsed after a landslide generated by the 1596 Fushimi earthquake. Bidirectional muographic surveys detected a 4-8 m width low-density region at the top of the mound. These were interpreted as large-scale vertical cracks that caused the translational collapse process behind the rotational landslide that was already found in prior trench-survey-based works. The observations revealed that the mound already had intrinsic problem with the stability of the basic foundation before the earthquake.
These proof of concepts demonstrate the applicability of muography for geotechnical surveys and encourage the further studies for improving the protection of landscapes, economies and societies.
[1] Oláh, L., Tanaka, H. K. M., and Varga, D. Muography: Exploring Earth's Subsurface With Elementary Particles, 1st ed., Geophysical Monograph Series, Vol. 270, American Geophysical Union and John Wiley & Sons, ISBN 9781119723028, 2022.
[2] Oláh, L., et al.: CCC-based muon telescope for examination of natural caves, Geosci. Instrum. Method. Data Syst., 1, 229, https://doi.org/10.5194/gi-1-229-2012, 2012.
[3] Oláh, L., et al.: The first prototype of an MWPC-based borehole-detector and its application for muography of an underground pillar. Geophysical Exploration (J-STAGE), 71, 161-178, https://doi.org/10.3124/segj.71.161, 2018.
[4] Sakatani, Y., et al.: Research on the development of soundness analysis technology for Sabo-related infrastructure by muography (Part 1), Journal of the Japan Society of Erosion Control Engineering, ISSN 2433-0477, 85, 69, 2020. (In Japanese)
[5] Tanaka, H. K. M., Sumiya, K., and Oláh, L.: Muography as a new tool to study the historic earthquakes recorded in ancient burial mounds, Geosci. Instrum. Method. Data Syst., 9, 357, https://doi.org/10.5194/gi-9-357-2020, 2020.
How to cite: Oláh, L., Tanaka, H. K. M., Hamar, G., Miyamoto, S., Sakatani, Y., Mori, T., and Sumiya, K.: Muography as a novel complementary technique for geotechnical surveys , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2168, https://doi.org/10.5194/egusphere-egu22-2168, 2022.
