Bulletin of Engineering Geology and the Environment

, Volume 78, Issue 7, pp 5327–5343 | Cite as

Characteristics of weathered mudstone with X-ray computed tomography scanning and X-ray diffraction analysis

  • Tomihiko OhishiEmail author
  • Masahiro TerakawaEmail author
Original Paper


Large-scale deformation on a cut slope composed of mudstone from the Neogene was observed over time during excavation of the powerhouse area at the Rajamandala Hydroelectric Power Plant in Indonesia. This paper discusses the characteristics of the mudstone and the mechanisms of slope behavior. As a part of detailed research into the mudstone, X-ray Computed Tomography scanning (CT scanning) and X-ray diffraction (XRD) analysis were applied to core samples. The purpose of CT scanning was to visually observe inside the core samples in three dimensions. The CT scanning image, which was a set of numbered CT scans, exhibited a color tone corresponding to the soundness of the core samples and this can be an indicator of weathering grade. The extent of weathering of each core sample was classified quantitatively by the CT scanning image and CT number. The extent of weathering maintains objectivity in the engineering classification of rock mass, which is generally assessed by core sample observation and hammer impacts. XRD analysis is commonly applied to dried samples in order to clarify their mineral components, especially the content of swelling clay minerals such as smectite. This paper discusses, in addition, XRD analysis for field-wet samples, because it is considered that a number of interlayer water molecules in smectite may have changed while preparing dried samples. Smectite, because of the relatively high quantity of interlayer water molecules, could likely cause swelling and slaking.


Weathered mudstone Neogene X-ray CT scanning CT number Smectite Interlayer water molecules Slope deformation over time 



We would like to express our sincere appreciation for the great cooperation of Central Research Institute of Electric Power Industry, HI-TEC Inc. and NEWJEC Inc.


  1. Chigira M (1988) Chemical weathering of mudstone of the Pleistocene Haizume formation, Niigata Prefecture, Central Japan. J Geol Soc Jap 94(6):419–431CrossRefGoogle Scholar
  2. Clements B, Hall R (2007) Cretaceous to Late Miocene Stratigraphic and Tectonic Evolution of West Java. Proc Indonesian Petroleum Assoc Thirty-first Ann Convent ExhibitGoogle Scholar
  3. Earth Observation of Singapore, Subduction Zone Beneath Java, Bali and Lombok Inlands, Indonesia, from, Accessed 15 Nov 2018
  4. Florkiewicz A, Wanatowski D, Flieger-Szymanska M, Machowiak K, Yuan R (2018) Yield criteria for glaciotectonically deformed deposits. Eng Geol 239:136–143CrossRefGoogle Scholar
  5. Hayashi K, Yama M, Yoneda T (2005) Chemical weathering and deterioration of Poronai mudstone. Jap Soc Eng Geol 46(4):198–206CrossRefGoogle Scholar
  6. Japan Civil Engineering Consultants Association (2009) Consideration of deterioration concept of slope stability evaluation 2: 25–36Google Scholar
  7. Maru K, Shaw RD (1984) Ground Instability during Open Excavation at the Saguling Hydroelectric Project, West Java. Proc 4th Int Symp Landslides, Toronto 2:137–142Google Scholar
  8. Maruyama K, Kozima S (1994) A proposal of warning criterion for the landslide crisis dependent on the observation data of sliding distance, J Jap Landslide Soc 31(1)Google Scholar
  9. Murakami T (2013) Management summary of hydropower development in indonesia, Electric Power Civil Engineering Association, 365:90–91Google Scholar
  10. Otsubo Y, Matsumoto F, Sasaki T (2017) Core sample observation by use of a Helical X-ray computed tomography scanner. Electric Power Civil Eng Assoc (391): 81–86Google Scholar
  11. Public Works Research Institute. et al (2010) Measurement manual for borehole inclinometer at landslide Area: 53–56Google Scholar
  12. Sato T (2001) Characteristics and applications of clays. J Clay Sci Soc Jap 41(1):26–33Google Scholar
  13. Sowers GF (1988) Movement in the Powerhouse Excavation Saguling Project, Indonesia, second international conference on case histories in Geotech Eng from, Accessed 15 Nov 2018
  14. Takahama N Landslides and Geology in the Southern Part of West Jawa, Indonesia. Ann Rep Saigai-ken, Niigata University(2) 1080Google Scholar
  15. Takeda S, Komiya K, Takeuchi I (1998) A new sampling technique using air bubble boring: the hybrid method. Soil Mech Found 46(5):28–30Google Scholar
  16. Takeda S, Komiya K, Takeuchi I (2006) From air bubble boring: the hybrid method to a Core sampling system of high quality. Soil Mech Found 54(4):16–18Google Scholar
  17. Ueda K Deformation of rock mass caused by strike-slip faulting: 3D analysis of analogue models by helical X-ray. Comput Tomograp Civil Eng Res Lab Rep. No. N0039, from, Accessed 15 Nov 2018
  18. Wibowo A (2012) Outcrops overview of Rajamandala limestone: world class outcrops in West Java, , from, Accessed 15 Nov 2018
  19. Yoshikawa K (1986) Construction for soft rock ground, 3.4 tunneling construction on soft rock ground (1). Soil Mech Found 34(6):69–76Google Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.The Kansai Electric Power Co., Inc.OsakaJapan

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