1 / 27

Overview of geological situation for a possible T2KK detector site

2nd International Workshop on a Far Detector in Korea for the J-PARC Neutrino Beam July 13 - 14. 2006,   International Conference Hall,   SNU. Overview of geological situation for a possible T2KK detector site. 2006. 07. 14 Chang-Ha Ryu Geotechnical Division

heath
Download Presentation

Overview of geological situation for a possible T2KK detector site

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 2nd International Workshop on a Far Detector in Korea for the J-PARC Neutrino BeamJuly 13 - 14. 2006,   International Conference Hall,   SNU Overview of geological situation for a possible T2KK detector site 2006. 07. 14 Chang-Ha Ryu Geotechnical Division Korea Intitute of Geoscience & Mineral Resources (KIGAM) 韓 國 地 質 資 源 硏 究 院

  2. General procedure • Preliminary data collection •     - preliminary assessment •     - preliminary geotechnical characterization • Feasibility study • - engineering classification of rock mass • - feasibility assessment of tunneling problems & alternatives • Detailed site characterization • Stability analyses • Final design and construction Feedback loop

  3. Requirements • Area between 2.0 and 2.5 degree off-axis beam ( < 1 deg. ?) • Depth: ~ 1,000 m (uniform overburden in all direction) • Size of underground research module: 50 m (dia.) x 280m (l) cylindrical opening • Long term safe operation • Effective (economic) construction • Research module in good rock mass

  4. Requirements_Location 2.5 deg. off axis 2.5deg.off-axis beam @Kamioka JPARC Off-axis angle 2.0 deg. off axis

  5. Geology of Korea

  6. Overview of General Geology • Throughout the country, mountains are not high, rarely exceeding 1,200 meters, but they are found almost everywhere. The terrain is rugged and steep, and only near the west and southwest coasts are extensive flat alluvial or diluvial plains and more subdued rolling hilly lands. • Korea consists largely of the Precambrian rocks, such as granite gneisses and other metamorphic rocks. The Gyeongsang Supergroup is distributed across a wide area within the Gyeongsang-do province which is one of the area of our concerns. • The Gyeongsang Supergroup is composed of the Sindong and Hwayang groups and the Bulguksa Intrusives. The biotite granite intruded in the Gyeongsang Supergroup is called Bulguksa Granite. Hwayang Group widely distributed throughout the Gyeongsang-do province, consists of conglomerates, sandstone, shale, and volcanic rock such as andesite, basalt, rhyolite, and tuff, especially in the upper part of the group.

  7. Site Consideration 1 • Overburden: 1 km deep • Preferrable site: mountain, mine, tunnel • Easy slope topograpy requires - excavation of long tunnel to satisfy gradient condition - shaft, inclined shaft toocostly !

  8. Mine Site Advantages of utilizing abandoned mine • Reduce costs • Minimize environmental impacts • Minimize complaints from residents and environmentalist • Easy to get approval and to get support from local government • Easy to get information on geological conditions

  9. URLs for Astrophysics Research_Mine Site Soudan URL Old iron mine in Minesota • Depth : 710m (2,080mwe) • Exp. Lab. : 15m x 13m x 82m SNO (Sudbury Neutrino Observatory) – Canada Location : Creighton mine, Sudbury Depth : 2,039m Boulby Mine Lab. - UK Location : Boulby mine, Cleveland Depth : 1,100m CUPP Lab. - Finland Location : Outokumpu mine, Pyhasalmi Depth : 90~970m (current)

  10. URLs for Astrophysics Research_Tunnel Site LNGS (Gran Sasso National Lab.) – Italy besides Gran Sasso tunnel (Teramo – Rome) Depth : 1,400m Experiment halls : L=100m, H=18m, LSC-Spain inside Somport tunnel (Spain – France), Canfranc Depth : ~ 900m

  11. Site Consideration_2~2.5deg. off-axis

  12. Site Consideration_ < 1deg. off-axis

  13. Geological Sheets

  14. Possible Sites

  15. Possible Sites

  16. Possible Site: Geological map - Eon Yang Sheet 1208m

  17. Site Consideration_2005 Bohyeon San (1124m) • Bohyeon San in Youngcheon ~1,045 km, 2.0o off, 1124 m high National Astronomy Observatory on top

  18. Possible Site: <1 degree off-axis • Guryongpo in Pohang (Gyeongbuk Province) • < 1,000 km • < 1.0o off, no mountains (sea level) • Toham San in Gyeongju • 1,000 km • 1.0o off, ~500 m high mountains (National Park)

  19. Description of Geology EON YANG Sheet: High mountaineous districts includes the peaks of Gajisan(1240m), Shinbulsan(1208m), in the western part, underlain by andesite, granite, and other rocks GI GAE Sheet: Southern marginal portion of the Taeback Mountain Range; the highest peak 960m(Giryoungsan); Bohyounsan(839m), Suseokbong(820m), Chimgoksan 725m, Unjusan 807m; the area is underlain by Cretacous sedimentary, volcanic and plutonic rocks- granite, granodiorite, andesite, rhyolite …

  20. Geological map of GI GAE sheet _1:50000

  21. Other Sites • SHINSHEUNG Sheet: Noreong mountain range, many peaks attain heights of between 400-760m; Sinseon-bong(763m), Choowolsan; gneiss, granite, sedimentary and volcanic rocks • MIRYANG Sheet There are comparatively high peaks of Togoksan(855m), Yomsubong(816m), Muchoksan(700m), Chontaesan(631m), Kumosan(760m), Hyangrobong(727m), Manosan(670m) etc. The geology of the area is composed of Yuchon Group and Bulguksa Intrusive rocks. The Yuchoon group is divided into andesitic rocks (andesite, ruff), and rhyolitic rocks (rhyolite, tuff); Miryang andesite is distributed on a large scale.

  22. Possible Site: <1 degree off-axis • Geological map – Guryogpo/Yeonil Sheet • 1:50,000 geological maps of these area: unavailable • Geological data and some detailed site information available • high speed rail way construction • roadway construction

  23.   Province   Coal mine Metal, Non-metal mine  A  B  C  D  A  B  C  D  Gangwon-do  5  1  3  5  6  7  3  Gyeonggi-do  1  2  2  Chungbuk-do  4  4  Chungnam-do  8  3  1 Jeonnambuk-do  2  2  Gyeongbuk-do  1  1  4  1  Gyeongnam-do  1  1 Mines Abandoned Mines * Possibility of utilization: A>B>C>D (source: KIGAM report, 2004) EX) List of Metal Mines in MUJU-gun (source: KIGAM Mine DB) 가옥, 강창, 고길, 금령(2), 길산, 동왕(1), 무주, 봉소(2), 삼가(1), 삼가(3), 삼가리, 삼봉(3), 삼성(3), 세창(2), 승륭, 쌍봉(1), 쌍봉(2), 쌍봉(3), 영성, 오동, 오산(2), 월성, 적상, 전일(1), 제국(1), 창덕(1), 태성, 태정 Mine layout, Samga mine

  24. Abandoned Quarry near Miryang ~ 1.5 km tunnel Location: Gyeongsangbuk-do Cheongdo-gun Rock type: Andesite Uni-axial compressive strength: 1,500 ~ 1,600 kgf/cm2 quarry

  25. Possible Site 478 m

  26. Concluding Remarks • Possible sites - mountain area - need to investigate mines thoroughly, and then find new site • Geological conditions - favorable - if poor but no other choice, solve by engineering - more detailed geotechnical characterization needed to reduce potential risks for construction

  27. Concluding Remarks • Factors affecting the stability of tunnels - stress fields - mechanical properties of rock: strength, E … - structural characteristics: joints, faults - groundwater conditions - method and quality of excavation - support of rock strata - size and shape of tunnel, underground chamber

More Related