| 1. |
T Esaki, M Zhang, A Takeshita, Y Mitani, Rigorous theoretical analysis of a flow pump permeability test, GEOTECHNICAL TESTING JOURNAL, Vol.19, No.3, pp.241-246, 1996.09, With the growing importance of environmental issues in our society, extremely low-permeability geotechnical materials are being studied increasingly for their long-term stability and effectiveness in retarding the transport of hazardous wastes. Relatively rapid measurements of the permeability and specific storage of the materials, using relatively low hydraulic gradients, can be obtained with a constant flow pump and the corresponding theoretical analysis proposed by Morin and Olsen (1987). However, the accuracy of this method is limited because their theoretical analysis does not take into account the storage capacity of the experimental system. This paper presents a more general theoretical analysis and shows how it can be used to determine not only the permeability and specific storage of a test specimen, but also the storage capacity of the experimental system. Experimental data are presented that illustrate the accuracy and efficiency of the general theoretical analysis.. |
| 2. |
M Zhang, T Esaki, HW Olsen, Y Mitani, Integrated shear and flow parameter measurement, GEOTECHNICAL TESTING JOURNAL, Vol.20, No.3, pp.296-303, 1997.09, Studies on the variation of permeability and the specific storage of bentonite-sand mixtures with shear deformations that may be caused by earthquakes and/or other geological events are of fundamental importance for long-term safety assessments of radioactive nuclear waste disposal facilities. This paper presents a recently developed and improved method for integrated shear and flow parameter measurements on a mixture of Kunigeru V1 Bentonite and D-Sand. This material will be used in low-level radioactive nuclear waste disposal facilities in Japan. The results of this study show that: (I) temperature control is important for measuring hydraulic parameters of low-permeability materials with the flow pump method; (2) shear strains up to about 3% did not significantly influence either the permeability or the specific storage of the bentonite-sand mixture; and (3) permeability and specific storage values interpreted from different time intervals during the transient rise and transient decay phases of the flow pump permeability tests were almost the same, which suggests that the reliability of both the experimental results and the newly derived theoretical analysis used to interpret the hydraulic parameters.. |
| 3. |
Evaluation of the Behavior of Underground Openings Using the New Base Friction Experimental Technique. |
| 4. |
T Esaki, S Du, Y Mitani, K Ikusada, L Jing, Development of a shear-flow test apparatus and determination of coupled properties for a single rock joint, INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES, 10.1016/S0148-9062(99)00044-3, Vol.36, No.5, pp.641-650, 1999.07, A new laboratory technique for coupled shear-flow tests of rock joints was developed and used to investigate the coupled effect of joint shear deformation and dilatancy on hydraulic conductivity of rock joints. This technique was used to carry out coupled shear-flow tests with an artificial created granite joint sample under constant normal loads and up to residual shear deformations of 20 mm. The hydraulic conductivity was estimated by using a finite difference method and an approximate equation assuming the cubic law. The shear-flow testing results revealed that the change of hydraulic conductivity is approximately similar to that of the dilatancy of a joint. The hydraulic conductivity increases rapidly, by about 1.2-1.6 orders of magnitude for the first 5 mm of shear displacement. After passing the residual shear stress, the hydraulic conductivity becomes gradually a constant value with increasing shear displacement. On the other hand, the hydraulic conductivity after shearing is about one order of magnitude larger than that prior to shearing. Shear-flow coupling characteristics obtained from these tests have a consistent trend with Barton's model prediction during the initial shear process. However, increasing deviation between measured and predicted hydraulic conductivity of rock joint samples has been observed with increasing shear displacement. (C) 1999 Elsevier Science Ltd. All rights reserved.. |
| 5. |
MW Xie, T Esaki, GY Zhou, Y Mitani, Three-dimensional stability evaluation of landslides and a sliding process simulation using a new geographic information systems component, ENVIRONMENTAL GEOLOGY, 10.1007/s00254-002-0655-3, Vol.43, No.5, pp.503-512, 2003.02, In this paper, based on a column-based three-dimensional (3-D) slope-stability analysis model, a new geographic information systems (GIS) grid-based 3-D deterministic model is developed. Assuming the initial slip as the lower part of an ellipsoid, the identification of the 3-D critical slip surface in the 3-D slope-stability analysis is performed by means of a minimization of the 3-D safety factor using the Monte Carlo random simulation. Using this 3-D GIS grid-based model and the GIS data for sliding process simulation, the landslide body will slide directing in the main slip inclination direction until its safety factor is up to 1. All the calculations are implemented by a computational program called 3-DSLOPEGIS, where a GIS component is used to fulfill the GIS spatial analysis function.. |
| 6. |
G Zhou, T Esaki, Y Mitani, M Xie, J Mori, Spatial probabilistic modeling of slope failure using an integrated GIS Monte Carlo simulation approach, ENGINEERING GEOLOGY, 10.1016/S0013-7952(02)00241-7, Vol.68, No.3-4, pp.373-386, 2003.03, Spatial probabilistic modeling of slope failure using a combined Geographic Information System (GIS), infinite-slope stability model and Monte Carlo simulation approach is proposed and applied in the landslide-prone area of Sasebo city, southern Japan. A digital elevation model (DEM) for the study area has been created at a scale of 1/2500. Calculated results of slope angle and slope aspect derived from the DEM are discussed. Through the spatial interpolation of the identified stream network, the thickness distribution of the colluvium above Tertiary strata is determined with precision. Finally, by integrating an infinite-slope stability model and Monte Carlo simulation with GIS, and applying spatial processing, a slope failure probability distribution map is obtained for the case of both low and high water levels. (C) 2002 Elsevier Science B.V. All rights reserved.. |
| 7. |
MW Xie, T Esaki, GY Zhou, Y Mitani, Geographic information systems-based three-dimensional critical slope stability analysis and landslide hazard assessment, JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING, 10.1061/(ASCE)1090-0241(2003)129:12(1109), Vol.129, No.12, pp.1109-1118, 2003.12, In this paper, by combining the geographic information systems (GIS) spatial analysis function and a hydrologic analysis and modeling tool with a column-based three-dimensional (3D) slope stability analysis model, a new GIS grid-based 3D deterministic model has been developed for slope stability analysis. Assuming the initial slip as the lower half of an ellipsoid, the identification of the 3D critical slip surface in the 3D slope stability analysis is performed by means of a minimization of the 3D safety factor using Monte Carlo random simulation. By using this hydrologic analysis and modeling tool, dividing the whole study area into slope units, and taking each slope unit as a study object, the minimum 3D safety factor for each slope unit can be obtained, and the landslide hazard can then be mapped for the whole study area.. |
| 8. |
Establishment of autonomously-distributed GIS and application to the campus map. |
| 9. |
GISを用いたトンネル湧水・渇水予測システムの開発. |
| 10. |
難透過性材料の高精度な流体移動特性評価のための理論的・実験的検討. |
| 11. |
Development and GIS analysis of 100m-mesh land-use map series for the past 100 years. |
| 12. |
実験方式の違いによる岩盤不連続面のせん断‐透水同時特性に関する研究. |
| 13. |
GISを用いたトンネル掘削に伴う湧水および水循環系の影響評価. |
| 14. |
GISによる阿蘇火砕流堆積物の分布と浸食過程の解析. |
| 15. |
遠賀川流域の土地利用の変遷に関する研究(律令期の土木技術の普及). |
| 16. |
遠賀川流域の土地利用の変遷に関する研究(古墳時代までの土木技術と土地開発). |
| 17. |
遠賀川流域の土地利用の変遷に関する研究(藩政期の河道変遷). |
| 18. |
Construction of sharing and circulating method for various information in the restoration project of Japanese crested ibis. |
| 19. |
GIS analysis on landform change of Aso pyroclastic flow deposit distributed at eastern area of Mt. Aso. |
| 20. |
Yasuhiro Mitani, Keigo Kitamura, Hiroyuki Honda, Mechanism of a Low Permeable Rock Injected by Supercritical CO2 for Non-Structural Storage Media, 2019.09. |
| 21. |
Tsuneo SEKIJIMA, Yoichi KAWAGUCHI, Tadashi MIYASHITA, Yasuhiro MITANI, Ryugo WATANABE, Restoration scenario and capacity building for resettlement Crested Ibis, 2010.12. |
