Laboratory reproduction of weathering and deterioration of soft-rock slopes and its application to disaster mitigation.

• Project/Area Number: 21246076
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Geotechnical engineering
• Research Institution: The University of Tokyo
• Principal Investigator: TOWHATA Ikuo 東京大学, 大学院・工学系研究科, 教授 (20155500)
• Co-Investigator(Kenkyū-buntansha): UCHIMURA Taro 東京大学, 大学院・工学系研究科, 准教授 (60292885) ; YAMADA Suguru 東京大学, 大学院・工学系研究科, 助教 (70451789)
• Project Period (FY): 2009 – 2011
• Project Status: Completed (Fiscal Year 2011)
• Budget Amount: ¥40,950,000 (Direct Cost: ¥31,500,000、Indirect Cost: ¥9,450,000); Fiscal Year 2011: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2010: ¥17,810,000 (Direct Cost: ¥13,700,000、Indirect Cost: ¥4,110,000); Fiscal Year 2009: ¥18,850,000 (Direct Cost: ¥14,500,000、Indirect Cost: ¥4,350,000)
• Keywords: 物理的風化 / 岩石 / 三軸圧縮試験 / ポイントローディング / 斜面崩壊 / 化学的風化 / S波伝播速度 / 凍結融解 / せん断強度 / 室内実験 / 現場実験 / 温度効果 / 軟岩 / S波速度 / 一軸圧縮 / 三軸圧縮

Research Abstract

Physical weathering of rock material induces loss of rigidity and deterioration of strength. This process was first reproduced in a newly developed testing device in which water-submergence, freezing, and heating were repeated. This test was able to reproduce the said rigidity loss and strength deterioration. Second, field studies were made in slope instability areas in both Japan and Pakistan where slope disasters have been significant. By using the knowledge thus collected, a methodology was developed by which the temporal progress of weathering and deterioration is traced and the mitigation of slope disaster is initiated at a critical time when the instability is imminent.

Research Products

• [Journal Article] Geotechnical aspects of the Sumatra earthquake of September 30, 2009, earthquake (2011)
  • Author(s): Gratchev, I., Irsyam, M., Towhata, I., Muin, B., Nawir, H.
  • Journal Title: Soils and Foundations Volume: 51 Pages: 333-341
  • Peer Reviewed
• [Journal Article] Analysis of the mechanisms of slope failures triggered by the 2007 Chuetsu Oki Earthquake (2011)
  • Author(s): Gratchev, Ivan, Towhata, I.
  • Journal Title: Geotechnical and Geological Engineering Volume: 29 Pages: 695-708
  • Peer Reviewed
• [Journal Article] Experimental study on negative ageing of granular soils in relation togeotechnical hazards (2010)
  • Author(s): Mubashir Aziz, Towhata, I., Yamada, S.
  • Journal Title: Natural Hazards and Earth System Sciences Volume: 10 Pages: 1229-1238
  • Peer Reviewed
• [Journal Article] Geotechnical properties of weathered slopes in Muzaffarabad area after the 2005 Kashmir-Earthquake (2010)
  • Author(s): Aziz, M., Qureshi, M.U., Yamada, S., Towhata, I., Khan, M.S.
  • Journal Title: Journal of Harbin Institute of Technology Volume: 16 Pages: 6-11
  • Peer Reviewed
• [Journal Article] Geotechnical structure damages during the 2009 Typhoon Morakot (2010)
  • Author(s): Lee, W.F., Towhata, I.
  • Journal Title: Bulletin of ISSMGE Volume: 4 CD-ROM
• [Journal Article] Geotechnical properties of weathered slopes in Muzaffarabad area after the 2005 Kashmir-Earthquake (2009)
  • Author(s): Aziz, M., Qureshi, M.U., Yamada, S., Towhata, I., Khan, M.S.
  • Journal Title: Journal of Harbin Institute of Technology(ISSN 1005-9113) 16 Sup.1 Pages: 6-11
  • Peer Reviewed
• [Journal Article] Geotechnical properties of weathered slopes in Muzaffarabad area after the 2005 Kashmir-Earthquake
  • Author(s): Aziz, M., Qureshi, M. U., Yamada, S., Towhata, I. and Khan. M. S.
  • Journal Title: Journal of Harbin Institute of Technology Volume: 16 Pages: 6-11
• [Presentation] The effects of weathering on strength and deformation characteristics of soft rocks (2011)
  • Author(s): Qureshi, M.U., Towhata, I., Yamada, S., Aziz, M.
  • Organizer: Int.Conf.Geotechnical Engineering
  • Place of Presentation: Lahore, Pakistan
  • Year and Date: 2011-11-05
• [Presentation] Effects of water-induced deterioration of grains on stiffness and strength of granular soils (2011)
  • Author(s): Aziz, M., Towhata, I., Yamada, S.
  • Organizer: IS Seoul
  • Place of Presentation: ソウル、韓国
  • Year and Date: 2011-09-02
• [Presentation] Evaluation of mechanical parameters of weathered slopes by several insitu geotechnical surveys (2011)
  • Author(s): Yamada, S., Towhata, I., Qureshi, Mohsin U.
  • Organizer: 10^<th> Asian Regional Conference on Soil Mechanics and Geotechnical Engineering
  • Place of Presentation: 香港、中国
  • Year and Date: 2011-05-23
• [Presentation] Earthquake-induced slope failures: Recent events and consequences (2011)
  • Author(s): Towhata, I., Aziz, Mubashir
  • Organizer: 5th International Conference on Earthquake Geotechnical Engineering
  • Place of Presentation: Santiago, Chile
  • Year and Date: 2011-01-12
• [Presentation] Evaluation of mechanical parameters of weathered slopes by several insitu geotechnical surveys (2011)
  • Author(s): Yamada, S., Towhata, I., Qureshi, Mohsin U.
  • Organizer: 10^<th> Asian Regional Conference on Soil Mechanics and Geotechnical Engineering
  • Place of Presentation: Hong Kong Hong Kong Special Administrative Region of People's Republic of China
• [Presentation] Long term effects of strong earthquake shaking on slope instability; Lessons from recent seismic events (2010)
  • Author(s): Towhata, I., Yamada, S., Toyota, H., Qureshi, M.U.
  • Organizer: 14th European Conference on Earthquake Engineering
  • Place of Presentation: Ohrid, Macedonia
  • Year and Date: 2010-08-30
• [Presentation] In-situ direct shear tests on weathered rock materials for slope failure risk assessment (2009)
  • Author(s): Qureshi, M.U.
  • Organizer: International Joint Symposium on Geodisaster Prevention and Geoenvironment in Asia, Fukuoka.
  • Place of Presentation: 福岡ガーデンパレス(福岡)
  • Year and Date: 2009-11-24
• [Presentation] Recent problems in earthquake-induced slopefailure and use of Monitoring (2009)
  • Author(s): Towhata, I.
  • Organizer: First International Seminar on Sustainable Infrastructure and Built Environment in Developing Countries.
  • Place of Presentation: Institut Teknologi Bandung(Bandung, Indonesia)
  • Year and Date: 2009-11-02
• [Presentation] Geotechnical aspects of 2008 Wenchuan earthquake (2009)
  • Author(s): Towhata, I.
  • Organizer: XVIIth International Conference on Soil Mechanics and Geotechnical Engineering, Alexandria.
  • Place of Presentation: Bibliotheca Alexandrina(Alexandria, Egypt)
  • Year and Date: 2009-10-06
• [Presentation] Field Investigations of highly weathered slopes for geotechnical risk ass (2009)
  • Author(s): Qureshi, M.U.
  • Organizer: 2nd International Conference on New Developments in Soil Mechanics and Geotechnical Engineering.
  • Place of Presentation: Near East University(Nicosia, North Cyprus)
  • Year and Date: 2009-05-28
• [Presentation] Geotechnical risk assessment of highly weathered slopes using seismic refraction technique (2009)
  • Author(s): Aziz, M.
  • Organizer: IS Kyoto 2009 Int.Symp.on Prediction and Simulation Methods for Geohazard Mitigation.
  • Place of Presentation: 国立京都国際会館(京都)
  • Year and Date: 2009-05-26
• [Presentation] Water submergence effects on geotechnical properties of crushed mudstone (2009)
  • Author(s): Aziz, M.
  • Organizer: IS Kyoto 2009 Int.Symp. on Prediction and Simulation Methods for Geohazard Mitigation.
  • Place of Presentation: 国立京都国際会館(京都)
  • Year and Date: 2009-05-26
• [Presentation] Geotechnical risk assessment of highly weathered slopes using seismic refraction technique
  • Author(s): Qureshi, M. U., Towhata, I., Yamada, S., Aziz, M., and Aoyama, S.
  • Organizer: Proc. IS Kyoto 2009 Int. Symp
  • Place of Presentation: On Prediction and Simulation Methods for Geohazard Mitigation
• [Presentation] Water submergence effects on geotechnical properties of crushed mudstone
  • Author(s): Aziz, M., Towhata, I., Yamada, S., and Qureshi, M. U.
  • Organizer: Proc. IS Kyoto 2009 Int. Symp
  • Place of Presentation: On Prediction and Simulation Methods for Geohazard Mitigation
• [Presentation] Field Investigations of highly weathered slopes for geotechnical risk assessment
  • Author(s): Qureshi, M. U., Towhata, I., Yamada, S., Aziz, M., and Kubo, Y.
  • Organizer: Proc. 2^<nd> International Conference on New Developments in Soil Mechanics and Geotechnical Engineering
  • Place of Presentation: Near East University, Nicosia, North Cyprus
• [Presentation] Evaluation of mechanical parameters of weathered slopes by several insitu geotechnical surveys
  • Author(s): Yamada, S., Towhata, I., and Qureshi, Mohsin U.
  • Organizer: Proc. 10^<th> Asian Regional Conference on Soil Mechanics and Geotechnical Engineering
  • Place of Presentation: Hong Kong
• [Presentation] The effects of weathering on strength and deformation characteristics of soft rocks
  • Author(s): Qureshi, M. U., Towhata, I., Yamada, S., and Aziz, M.
  • Organizer: Proc. Int. Conf. Geotechnical Engineering
  • Place of Presentation: Lahore
• [Presentation] A simplified technique for slope stability assessment based on insitu S-wave velocity measurement
  • Author(s): Qureshi, Mohsin Usman, Yamada, S. and Towhata, I.
  • Organizer: International Symposium on The Earthquake-induced Landslides
  • Place of Presentation: ISEL-Kiryu