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Nakayama, Masashi; Niunoya, Sumio*; Minamide, Masashi*
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 23(1), p.25 - 30, 2016/06
In Japan, any high-level radioactive waste repository is to be constructed at over 300m depth below surface. Tunnel support is used for safety during the construction and operation, and shotcrete and concrete lining are used as the tunnel support. Concrete is a composite material comprised of aggregate, cement and various additives. Low alkaline cement has been developed for the long term stability of the barrier systems whose performance could be negatively affected by highly alkaline conditions arising due to cement used in a repository. Japan Atomic Energy Agency (JAEA) has developed a low alkaline cement, named as HFSC (Highly fly-ash contained silicafume cement), containing over 60wt% of silica-fume (SF) and coal ash (FA). JAEA is presently constructing an underground research laboratory (URL) at Horonobe for research and development in the geosciences and repository engineering technology. HFSC was used experimentally as the shotcrete material in construction of part of the 350m deep gallery in Horonobe URL in 2013. The objective of this experiment was to assess the performance of HFSC shotcrete in terms of mechanics, workability, durability, and so on. HFSC used in this experiment is composed of 40wt% OPC (Ordinary Portland Cement), 20wt% SF, and 40wt% FA. This composition was determined based on mechanical testing of various mixes of the above components. Because of the low OPC content, the strength of HFSC tends to be lower than that of OPC in normal concrete. The total length of tunnel constructed using HFSC shotcrete is about 112m at 350m deep drift. The workability of HFSC shotcrete was confirmed by this experimental construction. In this report, we present detailed results of the in-situ construction test.
Motoshima, Takayuki*; Yabuki, Yoshio*; Minamide, Masashi*; Nago, Makito*; Aoyagi, Kazuhei
Tonneru Kogaku Hokokushu (CD-ROM), 24, p.I_10_1 - I_10_5, 2014/12
Economic tunnel support design for Horonobe underground research laboratory was obtained according to the relationship in the direction of the initial stress and the direction of excavation. The authors compared between the in situ convergence results and calculated results in order to investigate the validity of initial stress measurements. As a result, a positive correlation was observed between the in situ convergence results and calculated results, and the difference between the two was able to be explained by the difference between the assumed deformation coefficient and the measured coefficient. From these results, the measurement results of the initial stress performed in the surface based investigation has been confirmed almost reasonable.
Nago, Makito*; Hagihara, Takeshi*; Minamide, Masashi*; Motoshima, Takayuki*; Jin, Kazumi; Kudo, Hajime; Sugita, Yutaka; Miura, Yoichi*
Dai-49-Kai Zenkoku Kensetsugyo Rodo Saigai Boshi Taikai Kenkyu Rombunshu (CD-ROM), p.77 - 80, 2012/10
This paper presents measures against gas emission during deep shaft excavation in the Horonobe Underground Research Laboratory Project (Horonobe URL Project). The gas control measures taken in the Horonobe URL Project include the following: (1) determination of the amount of methane contained in surrounding strata and groundwater, and gas concentration based on preliminary investigations, (2) determination of the specifications of fans, dust collectors, and ducts through ventilation network analysis (simulation), (3) reduction of methane gas emission through the use of waterproofing grout, (4) prohibition on the use of internal-combustion engine and the adoption of explosion-proof equipment, (5) development of methane gas control system, and (6) monitoring of methane gas emission. (3) to (6) described above are performed daily in the safety management activities and described in detail in this paper. The ventilation and eastern access shafts have currently reached a depth of 290 m and 250 m, respectively. The emission of methane gas has been observed to rise 0.3 % to 1.3 % in the fault zone, and it is controlled appropriately according to the gas control measures described above. As the measure to reduce the methane gas concentration, monitoring is confirmed to be effective.
Nakayama, Masashi; Sato, Haruo; Sugita, Yutaka; Ito, Seiji*; Minamide, Masashi*; Kitagawa, Yoshito*
Proceedings of 13th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2010) (CD-ROM), p.51 - 56, 2011/01
In Japan, any high level radioactive waste repository is to be constructed at over 300 m depth below surface. Tunnel support is used for safety during the construction and operation, and shotcrete and concrete lining are used as the tunnel support. Concrete is a composite material comprised of aggregate, cement and various additives. Low alkaline cement has been developed for the long term stability of the barrier systems whose performance could be negatively affected by highly alkaline conditions arising due to cement used in a repository. Japan Atomic Energy Agency (JAEA) has developed a low alkaline cement, named as HFSC (Highly fly-ash contained silicafume cement), containing over 60wt% of silica-fume (SF) and fly-ash (FA). HFSC was used experimentally as the shotcrete material in construction of part of the 140 m deep gallery in Horonobe URL. The objective of this experiment was to assess the performance of HFSC shotcrete in terms of mechanics, workability, durability, and so on. HFSC used in this experiment is composed of 40wt% OPC (Ordinary Portland Cement), 20wt% SF, and 40wt% FA. This composition was determined based on mechanical testing of various mixes of the above components. Because of the low OPC content, the strength of HFSC tends to be lower than that of OPC in normal concrete. The total length of tunnel using HFSC shotcrete is about 73 m and about 500 m of HFSC was used. The workability of HFSC shotcrete was confirmed in this experimental construction.
Kuji, Masayoshi*; Matsui, Hiroya; Hara, Masato; Minamide, Masashi*; Mikake, Shinichiro; Takeuchi, Shinji; Sato, Toshinori*; Asai, Hideaki
JAEA-Research 2008-095, 54 Pages, 2009/01
A large amount of water inflow is frequently generated during the excavation of an underground cavern, such as road and railway tunnels, underground electric facilities etc. The reduction of water inflow is sometimes quite important for the reduction of cost for the water treatment and pumping during the construction of an underground cavern. The Mizunami Underground Research Laboratory (MIU) is currently being constructed by Japan Atomic Energy Agency. During its excavation, a large amount of water inflow into the shafts has been increasing and affecting the project progress. Therefore, a field experiment of post-excavation grouting around the Ventilation Shaft in a sedimentary formation carried out to confirm the effect of existing grouting technology for sedimentary formations in MIU project. The result shows that the applied methods in this field experiment are effective to prevent water inflow. This report describes the summary of the field experiment and the knowledge obtained through the experiment.
Yamazaki, Masanao; Tsusaka, Kimikazu; Hatsuyama, Yoshihiro*; Minamide, Masashi*; Takahashi, Akihiro*
Dai-38-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koen Rombunshu (CD-ROM), p.196 - 201, 2009/01
The Underground Research Laboratory in Hokkaido has been constructed by JAEA. In shaft excavation, convergence, lining stress, etc. are measured and analyzed in order to evaluate the validity of a support design. In this report, correlation between initial deformation ratio of convergence and lining stress in shaft excavation is discussed. Prediction equation of the lining stress from the initial deformation ratio of convergence in the short step method is also proposed.
Kuji, Masayoshi; Sato, Toshinori; Mikake, Shinichiro; Hara, Masato; Minamide, Masashi; Sugihara, Kozo
Journal of Power and Energy Systems (Internet), 2(1), p.153 - 163, 2008/00
The Mizunami Underground Research Laboratory (MIU) is being constructed. The MIU consists of two 1,000 m-deep shafts with several research galleries. The goals of MIU project are to establish techniques for investigation, analysis and assessment of deep geological environment, and to develop a range of engineering expertise for application to deep underground crystalline rocks, such as Granite. The diameter of the Main and the Ventilation shafts are 6.5 m and 4.5 m respectively. The Middle stage at about 500 m depth, and the Main stage at about 1,000 m depth will be the main locations for scientific investigations. Current depths of both shafts are 200 m, in August 2007.During the construction, the water inflow into the shafts is increasing and disturbing the project progress. For reducing the water inflow, post-excavation grouting was planned. A test of post-excavation grouting was undertaken and the applicability of several techniques was evaluated.
Kuji, Masayoshi; Sato, Toshinori; Mikake, Shinichiro; Hara, Masato; Minamide, Masashi; Sugihara, Kozo
Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 7 Pages, 2007/04
The Mizunami Underground Research Laboratory (MIU) is being constructed. The MIU consists of two 1,000 m-deep shafts with several research galleries. The diameter of the shafts are 6.5 m and 4.5 m, respectively. Horizontal tunnels to connect the shafts are excavated at 100 m depth intervals. The Middle stage, at about 500 m depth, and the Main stage at about 1,000 m depth will be the main locations for scientific investigations. Current depths of shafts are 180 m and 191 m respectively, in November, 2006. During the construction, the quantity of water inflow into the shafts is increasing and disturbing the project progress. In order to reduce the quantity of water inflow, post-excavation grouting and pre-excavation grouting are planned. A test of post-excavation grouting was undertaken in the Ventilation shaft and the applicability of several techniques were evaluated.
Kuji, Masayoshi; Sato, Toshinori; Hara, Masato; Mikake, Shinichiro; Minamide, Masashi
Tonneru Kogaku Hokokushu (CD-ROM), 16, p.469 - 476, 2006/11
In the Mizunami Underground Research Laboratory (MIU), two 1,000m-deep shafts and several research galleries are being constructed. Water inflow into the shafts during shaft sinking is disturbing the project progress. As a countermeasure for this problem, post-grouting is being considered and post-grouting test has been undertaken in one of the shafts. This report gives an outline of the work plan and results of the post-grouting test.
Hara, Masato; Kuji, Masayoshi; Minamide, Masashi; Mikake, Shinichiro; Sato, Toshinori; Ikeda, Koki
no journal, ,
In the Mizunami Underground Research Laboratory, water inflow into the shafts is disturbing the project progress. As a countermeasure for this problem, pre-grouting is being considered and pre-grouting has been undertaken in the shafts. This report describes an outline of the work results of pre-grouting.
Kuji, Masayoshi; Hara, Masato; Minamide, Masashi; Mikake, Shinichiro; Sato, Toshinori; Ikeda, Koki
no journal, ,
no abstracts in English
Hara, Masato; Minamide, Masashi; Ikeda, Koki; Yamamoto, Masaru; Matsui, Hiroya; Kuji, Masayoshi
no journal, ,
As water inflow measure of the ventilation shaft, the articulated section and the pre- grouting which deals with the boring adit were executed, the water inflow depression effect was verified.
Hara, Masato; Kinoshita, Harunobu; Ikeda, Koki; Yamamoto, Masaru; Yahagi, Ryoji*; Kikuchi, Shinji*; Kawano, Hiromichi*; Ushida, Kazuhito*; Nobuto, Jun*; Minamide, Masashi*
no journal, ,
At the Mizunami Underground Research Laboratory, inflow water control to inside the tunnel has become topic. Because of this, the pre-grouting at inside the tunnnel of depth 200m was executed. In this report, it is something which is reported concerning the result of the pre-grouting.
Tsusaka, Kimikazu; Yamazaki, Masanao; Minamide, Masashi*; Hatsuyama, Yoshihiro*
no journal, ,
no abstracts in English
Kitagawa, Yoshito*; Yamazaki, Masanao; Hagihara, Takeshi*; Minamide, Masashi*; Sekiya, Yoshitomo
no journal, ,
no abstracts in English
Yamazaki, Masanao; Fukui, Katsunori*; Minamide, Masashi*; Hatsuyama, Yoshihiro*
no journal, ,
The correlation between the energy per unit excavated volume calculated from the electric power consumption of the road header during the shaft excavation and the rock properties observed at the excavation wall was investigated in the Horonobe Underground Research Project. As a result, it was found that the energy per unit excavated volume correlate better with the rock mass classification determined from both a fracture intensity as well as a rock strength rather than with a fracture intensity. We will continue to measure the electric power consumption data in order to establish rock mass evaluation method using the energy per unit excavated volume.
Noguchi, Akira; Nakayama, Masashi; Kishi, Hirokazu; Kitagawa, Yoshito*; Minamide, Masashi*
no journal, ,
We are researching about the low alkaline cement applying to support of galleries for high-level radioactive waste repositories. In March, 2009, we performed a experiment of shotcrete with low alkaline cement whose proportion of the binder is 40% of ordinary portland cement, 20% of silicafume and the rest 40% of flyash. By selecting the proportion 30% water binder ratio and adding superplasticizer, the slump was 23 cm and compressive strength of the hardened concrete was 38.3 MPa. This proportion satisfied the standard of the support of the Horonobe Underground Research Laboratory whose compressive strength is more than 36 MPa and slump is around 21cm. The rebound ratio of the shotcrete was around 13%. This value is lower than that of ordinary portland cement. So, we can expect to get a better construction environment with this shotcerte. We decided to use this proportion in the in-situ experiment at the 140 m gallery in the Horonobe URL.
Kitagawa, Yoshito*; Minamide, Masashi*; Nayuki, Toshinori*; Yamanishi, Takeshi; Sekiya, Yoshitomo; Ito, Seiji; Sato, Haruo; Nakayama, Masashi
no journal, ,
In Japan, any high level radioactive waste repository is to be constructed at over 300m depth below surface. Tunnel support is used for safety during the construction and operation, and shotcrete and concrete lining are used as the tunnel support. Concrete is a composite material comprised of aggregate, cement and various additives. Low alkaline cement has been developed for the long term stability of the barrier systems whose performance could be negatively affected by highly alkaline conditions arising due to cement used in a repository. Japan Atomic Energy Agency (JAEA) has developed a low alkaline cement, named as HFSC (High fly-ash silicafume cement), containing over 60wt% of silica-fume (SF) and coal ash (FA). JAEA are presently constructing an underground research laboratory (URL) at Horonobe for research and development in the geosciences and repository engineering technology. HFSC was used experimentally as the shotcrete material in construction of part of the 140m deep gallery in Horonobe URL. The objective of this experiment was to assess the performance of HFSC shotcrete in terms of mechanics, workability, durability, and so on. HFSC used in this experiment is composed of 40wt% OPC (Ordinary Portland Cement), 20wt% SF, and 40wt% FA. This composition was determined based on mechanical testing of various mixes of the above components. Because of the low OPC content, the strength of HFSC tends to be lower than that of OPC in normal concrete. The total length of tunnel using HFSC shotcrete is about 73m and about 500m of HFSC was used. This experimental construction confirmed the workability of HFSC shotcrete. Although several in-situ experiments using low alkaline cement as shotcrete have been performed at a small scale, this application of HFSC at the Horonobe URL is the first full scale application of low alkaline cement in the construction of a URL in the world.
Sawada, Sumiyuki; Tokiwa, Tetsuya; Kumagai, Seiya; Minamide, Masashi*
no journal, ,
Underground facilities have been excavated in soft sedimentary rocks in the Horonobe area, Hokkaido, Japan. Spring water induced by excavation is a major issue, and therefore it is need to implement the spring water control by pre-grouting before the excavation for the efficient and safety excavation. The flow point needed to inject the grouting had been calculated by using borehole investigation data (e.g., core observations and Fluid Electric Conductivity Logging), and boring for pre-grouting was carried out. As a result, calculated flow points are identical with actual flow points. Therefore, it is quite likely to assess and predict the flow points by focusing on borehole investigation data.
Hagihara, Takeshi*; Nago, Makito*; Minamide, Masashi*; Ogawa, Hiroyuki*; Uyama, Mikinori*; Demma, Keisuke*; Kisu, Yoshio*; Morimoto, Tsutomu*; Kudo, Hajime; Tsusaka, Kimikazu
no journal, ,
no abstracts in English