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Journal Articles

Effective 3D data visualization in deep shaft construction

Inagaki, Daisuke*; Tsusaka, Kimikazu*; Aoyagi, Kazuhei; Nago, Makito*; Ijiri, Yuji*; Shigehiro, Michiko*

Proceedings of ITA-AITES World Tunnel Congress 2015 (WTC 2015)/41st General Assembly, 10 Pages, 2015/05

Journal Articles

A Study of mechanical stability of support elements and surrounding rock mass during shaft sinking through a fault

Tsusaka, Kimikazu*; Inagaki, Daisuke*; Nago, Makito*; Ijiri, Yuji*

Proceedings of 8th Asian Rock Mechanics Symposium (ARMS-8) (USB Flash Drive), 9 Pages, 2014/10

JAEA Reports

Study on engineering technologies in the Mizunami Underground Research Laboratory; FY2009-2010 (Contract research)

Ijiri, Yuji*; Noda, Masaru*; Nobuto, Jun*; Matsui, Hiroya; Mikake, Shinichiro; Hashizume, Shigeru

JAEA-Technology 2013-047, 819 Pages, 2014/03

JAEA-Technology-2013-047-01.pdf:41.49MB
JAEA-Technology-2013-047-02.pdf:25.26MB

The researches on engineering technology in the Mizunami Underground Research Laboratory plan consists of (1) research on engineering technology at a deep underground, and (2) research on engineering technology as abasis of geological disposal. The former research mainly aimed in this study are categorized in (a) development of design and construction planning technologies, (b) development of construction technology, (c) development of countermeasure technology, (d) development of technology for security. In this study, the researches on engineering technology are proceeded in these four categories by using data measured down to GL-460m during construction as a part of the second phase of the MIU plan.

JAEA Reports

Study on development of evaluation technique of in-situ tracer test in Horonobe Underground Research Laboratory Project (Contract research)

Yokota, Hideharu; Amano, Kenji; Maekawa, Keisuke; Kunimaru, Takanori; Naemura, Yumi*; Ijiri, Yuji*; Motoshima, Takayuki*; Suzuki, Shunichi*; Teshima, Kazufumi*

JAEA-Research 2013-002, 281 Pages, 2013/06

JAEA-Research-2013-002.pdf:13.03MB

To evaluate permeable heterogeneity in a fracture and scale effects which are problems to be solved based on the ${it in-situ}$ mass transportation data of fractures in hostrock, a number of tracer tests are simulated in a fictitious single plate fracture generated on computer in this study. And the transport parameters, e.g. longitudinal dispersion length, true velocity and dilution rate, are identified by fitting one- and two-dimensional models to the breakthrough curves obtained from the simulations in order to investigate the applicability of these models to the evaluation of ${it in-situ}$ tracer test. As a result, one-dimensional model yields larger longitudinal dispersion length than two-dimensional model in the both cases of homogeneous and heterogeneous hydraulic conductivity fields of the fictitious fracture. And, the longitudinal dispersion length identified from a tracer test is smaller and/or larger than the macroscopic longitudinal dispersion length identified from whole fracture. It is clarified that these are occurred by shorter or longer distance between boreholes compare to the correlation length of geostatistical heterogeneity of fictitious fracture.

Journal Articles

A Study on rock mass behaviour induced by shaft sinking in the Horonobe Underground Research Laboratory

Tsusaka, Kimikazu; Tokiwa, Tetsuya; Inagaki, Daisuke; Hatsuyama, Yoshihiro*; Koike, Masashi*; Ijiri, Yuji*

Doboku Gakkai Rombunshu, F1 (Tonneru Kogaku) (Internet), 68(2), p.40 - 54, 2012/09

Japan Atomic Energy Agency has excavating three deep shafts through soft sedimentary rock at Horonobe Underground Research Laboratory. In this paper, the author discussed rock mass behaviour induced by the 6.5 m diameter shaft sinking. They conducted geological mapping in an excavation face and boreholes digged around the shaft wall, field measurements such as convergence measurements and monitoring of rock displacements using multi-interval borehole extensometers around a shaft at around 160 m and 220 m in depths, and three-dimensional numerical analysis which models the shaft excavation procedure such as timing of installation of support elements and setting and removal of a concrete form. As a result, it was clarified that remarkablely large compressive strains occurred within about 1 m into the shaft wall since the rock mass behaviour was controlled by the concrete lining and that the behaviour would predominantly be induced by the fractures closing which opened significantly and propagated during excavation steps before the installation of a concrete lining and the directions where the strains occurred heavily depended on the fracture orientation around the shaft.

JAEA Reports

Study on engineering technologies in the Mizunami Underground Research Laboratory; FY2008 (Contract research)

Ijiri, Yuji*; Noda, Masaru*; Sasakura, Takeshi*; Nobuto, Jun*; Matsui, Hiroya; Mikake, Shinichiro; Hashizume, Shigeru

JAEA-Technology 2012-018, 288 Pages, 2012/07

JAEA-Technology-2012-018.pdf:19.13MB

The researches on engineering technology in the Mizunami Underground Research Laboratory plan consists of (1) research on engineering technology at a deep underground, and (2) research on engineering technology as a basis of geological disposal. The former research mainly aimed in this study are categorized in (a) development of design and construction planning technologies, (b) development of construction technology, (c) development of countermeasure technology, (d) development of technology for security. In this study, the researches on engineering technology are proceeded in these four categories by using data measured down to GL-300m during construction as a part of the second phase of the MIU plan.

Journal Articles

A Study on mechanical behaviour of support elements induced by shaft sinking

Tsusaka, Kimikazu; Inagaki, Daisuke; Hatsuyama, Yoshihiro*; Koike, Masashi*; Shimada, Tomohiro*; Ijiri, Yuji*

Doboku Gakkai Rombunshu, F1 (Tonneru Kogaku) (Internet), 68(1), p.7 - 20, 2012/05

Japan Atomic Energy Agency has excavating three deep shafts through soft sedimentary rock at Horonobe Underground Research Laboratory. In this paper, the author discussed change in stress and the stress distribution in a concrete lining and steel arch sets induced by the 6.5 m diameter shaft sinking. They conducted not only field measurements of stress in support elements at around 220 m in depth but also three-dimensional numerical analysis which models the shaft excavation procedure such as timing of installation of support elements and setting and removal of a concrete form. As a result, it was clarified that more than 10 MPa difference in circumferential stress occurred in a 2 m high and 400 mm thick concrete lining due to anisotropy of initial stress and three-dimensional effect of an excavation face. It was also found that a concrete lining gradually deformed from an original cylindrical form to an "oval salad bowl" form with the long axis pallarel to the direction of the minimum horizontal principal stress after a concrete form was removed.

Journal Articles

Risk management methodology for construction of underground structures

Matsui, Hiroya; Ijiri, Yuji*; Kamemura, Katsumi*

Proceedings of ITA-AITES World Tunnel Congress 2012 (WTC 2012)/38th General Assembly (CD-ROM), 8 Pages, 2012/05

JAEA has been conducting research and development at two underground research laboratory projects, in crystalline and sedimentary rock at Mizunami, Gifu and Horonobe, Hokkaido respectively. In this report, individual risk assessment methods are shown based on existing studies on general underground construction projects and complementary data and experience obtained from the Mizunami URL project. The results suggest that risk assessments on geological disposal projects can utilize this methodology to assess risk in establishing the site description model for design and safety assessment of a repository, as was done in Phase I of the Mizunami URL. Thus the proposed methodology should have broad application and additional special investigations for risk management are not likely needed.

Journal Articles

A Study on mechanical behaviors of concrete lining and rock caused by shaft sinking at the Horonobe Underground Research Laboratory

Tsusaka, Kimikazu; Inagaki, Daisuke; Koike, Masashi*; Ijiri, Yuji*; Hatsuyama, Yoshihiro*

Harmonising Rock Engineering and the Environment, p.305 - 308, 2011/10

In this paper, the authors discussed circumferential stress distribution in a concrete lining and displacement of rock around shaft wall induced by shaft excavation at Horonobe Underground Research Laboratory. Field measurements of the lining stress and rock displacement were conducted between 218 m and 220 m in depths during excavation of a 6.5 m diameter access shaft and the results were analyzed using a three-dimensional numerical model. As a result, it was found that the maximum and minimum stresses occurred in the direction of horizontal minimum and maximum initial stresses, respectively. It was also clarified that difference in the stress between the maximum and minimum values was beyond 10 MPa. In addition, it was found that compressive axial strain occurred around a shaft wall after casting concrete lining since rock behavior in the vicinity of shaft wall was controlled by a concrete lining.

Journal Articles

Study on the behavior of concrete lining and rock mass during shaft excavation in the Horonobe URL Project, 1

Inagaki, Daisuke; Tsusaka, Kimikazu; Ijiri, Yuji*; Koike, Masashi*; Hatsuyama, Yoshihiro*

Dai-40-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koen Rombunshu (CD-ROM), 6 Pages, 2011/01

no abstracts in English

Journal Articles

A Study on the behaviour of concrete lining and rock mass during shaft excavation at the Horonobe URL project, 2

Tsusaka, Kimikazu; Inagaki, Daisuke; Koike, Masashi*; Ijiri, Yuji*; Hatsuyama, Yoshihiro*

Dai-40-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koen Rombunshu (CD-ROM), p.7 - 12, 2011/01

no abstracts in English

JAEA Reports

Mizunami Underground Research Laboratory project (Study on hydrogeology in crystalline fractured rock); Geo-risk management focused on water inrush using discrete fracture network model

Onoe, Hironori; Saegusa, Hiromitsu; Motoshima, Takayuki*; Ijiri, Yuji*; Otsu, Hiroyasu*

JAEA-Research 2010-021, 73 Pages, 2010/10

JAEA-Research-2010-021.pdf:6.1MB

It is important to evaluate the influence of water inrush into underground facility on costs and schedules for construction of deep underground facility based on prior information. In this study, risk assessment method using a combination of discrete fracture network model with financial engineering theory has been developed taking into account unexpected water inrush into the underground facility constructed in crystalline fractured rock. The risk assessment method has been applied to the construction of the Mizunami Underground Research Laboratory. The relationship between the amount of information due to the progress of investigations and the risk regarding cost variation for the countermeasure against water inrush has been evaluated. As a result, site characterization procedure for decreasing the water inrush risk efficiently was suggested. The applicability of the risk assessment method for the ex-post-facto assessment of construction of the underground facility was also confirmed.

JAEA Reports

Horonobe Underground Research Laboratory Project; The Results of the pilot borehole investigation of the ventilation shaft (PB-V01); Geophysical loggings

Funaki, Hironori; Asamori, Koichi; Sanada, Hiroyuki; Hatsuyama, Yoshihiro*; Yamamoto, Takuya*; Ijiri, Yuji*; Matsuoka, Kiyoyuki*; Kimura, Kazuhiro*; Lin, S.*; Kumagai, Toshifumi*

JAEA-Data/Code 2010-002, 151 Pages, 2010/06

JAEA-Data-Code-2010-002.pdf:43.13MB

JAEA is implementing Horonobe URL Project as research and development of geological disposal. The investigation of the pilot boring was carried out around the Ventilation shaft in order to decide grouting plan and plant of effluent treating. This report summarize as data-code results of geophysical loggings.

Journal Articles

A Study on risk assessement approach of water inflow into a shaft in fractured rock mass

Motoshima, Takayuki*; Onoe, Hironori*; Ijiri, Yuji*; Otsu, Hiroyasu*; Saegusa, Hiromitsu

Doboku Gakkai Rombunshu, C, 66(2), p.370 - 386, 2010/06

Since water inflow into a tunnel significantly impacts construction costs and schedules, it is important to estimate the impact on these factors quantitatively based on prior information about hydrogeological properties. A simplified formula is proposed in order to estimate water inflow volume into tunnel and is validated through comparing the results of DFN model. This formula is able to calculate water inflow risk more quickly than DFN model. Monte Carlo simulation and sensitivity analysis about water inflow risk are performed by using this formula. Then relationships between water inflow risk and amount of information about fracture properties are obtained based on the sensitivity analysis.

JAEA Reports

Studies on engineering technologies in the Mizunami Underground Research Laboratory; FY2007 (Contract research)

Noda, Masaru*; Suyama, Yasuhiro*; Nobuto, Jun*; Ijiri, Yuji*; Mikake, Shinichiro; Matsui, Hiroya

JAEA-Technology 2009-009, 194 Pages, 2009/07

JAEA-Technology-2009-009.pdf:44.14MB

In construction phase in MIU, the study on engineering technology consist of following four subjects, which are Demonstration of design methodology of a greatly deepr underground structure, Demonstration of excavation and supplymentary methods of a greatly deepr underground structure, Demonstration of the countermeasure during excavation of a greatly deepr underground structure and Demonstration of the safe construction for a greatly deepr underground structure. In the study in FY2007, the design methodlogy in Phase 1 is verified until 200 m depth on excavation of ventilation shaft. A plan, countermeasure and concept for influence of differential water pressure, long-term maintenance and risk management in the view of geological disposal project were proposed.

JAEA Reports

Horonobe Underground Research Laboratory project overview of the pilot borehole investigation of the ventilation shaft (PB-V01); Hydrogeological investigation

Yabuuchi, Satoshi; Kunimaru, Takanori; Ishii, Eiichi; Hatsuyama, Yoshihiro*; Ijiri, Yuji*; Matsuoka, Kiyoyuki*; Ibara, Tetsuo*; Matsunami, Shinjiro*; Makino, Akiya*

JAEA-Data/Code 2008-026, 62 Pages, 2009/02

JAEA-Data-Code-2008-026.pdf:8.23MB

The Pilot Borehole Investigation of the Ventilation Shaft was conducted in Horonobe, Hokkaido, Japan from October 2007 to March 2008. Main purpose of the investigation is to understand geological, hydrogeological and hydrochemical properties of the formation where the Ventilation Shaft has been excavated. Hydraulic packer tests show that hydraulic conductivity lies in the range from 1.1E-11 to 1.4E-7 m/sec down to 500 m in depth. This heterogeneity mainly depends on the distribution and permeability of groundwater inflow points, which were detected by Fluid Electric Conductivity logging. High conductive zones were found between 263 m and 290 m, 355 m and 370 m of the depth in the pilot borehole. An effective method for reducing groundwater inflow should be considered for the deeper Ventilation Shaft excavation.

Journal Articles

Evaluation of uncertainties originating from the different modeling approaches applied to analyze regional groundwater flow in the Tono area of Japan

Ijiri, Yuji*; Saegusa, Hiromitsu; Sawada, Atsushi; Ono, Makoto*; Watanabe, Kunio*; Karasaki, Kenji*; Doughty, C.*; Shimo, Michito*; Fumimura, Kenichi*

Journal of Contaminant Hydrology, 103(3-4), p.168 - 181, 2009/01

 Times Cited Count:7 Percentile:27.71(Environmental Sciences)

Qualitative evaluation of the effects of uncertainties originating from scenario development, conceptual models, and parameter values is an important subject in the area of safety assessment for high-level nuclear waste disposal. In this study, regional-scale groundwater flow analyses for the Tono area, Japan were conducted using three continuous models which were designed to handle heterogeneous porous media. We evaluated the simulation results to quantitatively analyze uncertainties originating from conceptual models. We found that uncertainties originating from conceptual models (1) greatly depend on boundary conditions and hydrological structures to be modeled, which are assigned by modelers, and (2) are larger than uncertainties originating from the variance in realizations of the Monte Carlo method in stochastic modeling.

Journal Articles

Study of the uncertainties in conceptual modeling for regional groundwater flow characterization

Ijiri, Yuji*; Saegusa, Hiromitsu; Sawada, Atsushi; Nakano, Katsushi; Ono, Makoto*

Chikasui Ryudo Kaiseki To Moderuka Ni Kansuru Shimpojium Happyo Rombunshu, p.67 - 76, 2007/01

no abstracts in English

Journal Articles

Uncertainty in groundwater flow simulations caused by multiple modeling approaches, at the Mizunami Underground Research Laboratory, Japan

Sawada, Atsushi; Saegusa, Hiromitsu; Ijiri, Yuji*

Dynamics of Fluids and Transport in Fractured Rock, Geophysical Monograph Series 162, p.91 - 101, 2005/00

This paper demonstrates an example to evaluate uncertainties involved in hy-drogeological modeling. This study was conducted by employing multiple mod-eling experts and/or conceptual models with defining performance measures (PMs) from the performance assessment of high level radioactive waste disposal point of view. Five hydrogeological model based on data obtained from the sur-face-based investigation phase at/around underground research laboratory con-struction site, Tono area, Gifu prefecture, Japan, and PMs calculated from the numerical simulations by each model were compared, and we found major un-certainties at the stage of site characterization.

Journal Articles

Uncertainty Evaluation of Groundwater Flow by Multiple Modeling Approach at Mizunami Underground Research Laboratory Project, Japan

Sawada, Atsushi; Saegusa, Hiromitsu; Ijiri, Yuji*

P.232-236, p.232 - 236, 2004/00

None

68 (Records 1-20 displayed on this page)