南海トラフのメタンハイドレート生産を想定した土の変形および強度特性に関する研究

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(1)eformation and shear strength characteristics of methane hydrate bearing sediments in Nankai Trough during gas production.

(2) <. >. 1. 1-1. 1.1. 1-1. 1.2. 1-3 1.2.1. 1-3. 1.2.2. 1-7. 1.2.3. 1-12. 1.2.4. 1-19 1-20. 1.3 1.3.1. 1-20. 1.3.2. 1-24 1-28. 1.4. 1-32. 2. 2-1. 2.1. 2-1. 2.2. 2-3 2.2.1. 2-3. 2.2.2. 2-8. 2.2.2.1. 2-8. 2.2.2.2. 2-10. 2.2.3 2.2.4. 2-13 2-15. PTV. 2.2.5. 2-18. 2.3. 2-21 2.3.1. 2-21. 2.3.2. 2-25. 2.4. 2-28 2.4.1. 2-28. 2.4.2. 2-34. 2.4.3. 2-41. 2.4.4. 2-42 i.

(3) <. >. 2.5. 2-44 2-45. 3-1. 3.1. 3-1. 3.2. 3-3. 3.3. 3-5. 3.4. 3-9 3.4.1. 3-9. 3.4.2. 3-11 3-14. 3.5. 3-15. 4. 4-1. 4.1. 4-1. 4.2. 4-2 4.2.1. 4-2. 4.2.2. 4-2. 4.2.3. 4-6. 4.3. 4-9. 4.3.1. 4-9. 4.3.2. 4-11. 4.3.3. 4-12. 4.3.4. 4-12. 4.4. 4-16 4.4.1. 4-16. 4.4.2. 4-16. 4.5. 4-22 4.5.1. 4-22. 4.5.2. 4-22. 4.6. 4-28 ii.

(4) <. > 4-29. 5. 5-1. iii.

(5) 1. 1. 1.1. 2011. 3. 11. 9.0. (. 2014). 5739 m3. (. LNG. ). 5.5. (. 2016). 21 LNG. LNG. (2012). LNG (2016) 2012 2012. 83.2%. 1-1. 99.6%.

(6) 1 LNG LNG. LNG MH. 28. 2. 30. (. 2. ). 3. 4. 1-2.

(7) 1 1.2. 1.2.1. 19. 19 (. ) 1940. (. 2009) 1999. (. 2007) 2002 5. 21. (. MH21). (. ). 6. 5. 3 1. 3. 2009. 2008. 2. 1. 2. 1-3. 1.

(8) 1 3. 1-2-1. 2012. 2. 2013. 8. 1. 2013 12. 18. 1-2-1. 6. MH21. 1-2- 1. MH. 1. (MH21. 1-4. ). 3.

(9) 1 1-2-1 (. ). 1810 1934 1965 1970. Blake-Bahama Outer Ridge DSDP. Leg-11. Reflector-Y. Stoll. DSDP. Hollister. Reflector-Y. Stoll. Reflector-Y. Scholl. Bering Bottom Simulating Reflector. BSR. DSDP Leg-19 BSR. Tucholke bottom simulating reflecting horizon Hein. , Bering. -A -CT. Shipley -simulating reflection. Hollister,1972. DSDP Leg-66 1980. BSR. BSR. ODP Leg-127 1990. (ODP Leg-131 Site808). 1-5.

(10) 1 Blake Ridge (TRC). ODP Leg.164 10. 2. NEDO Mackenzie Delta (. ). BSR 2002. (. ). (. ). 3 (. MH21). 2007. 2008. 2. 1. 2. 2. 2009. 1. 2009 2012. 2 1. 2013 2016. 3 2. 1-6.

(11) 1 1.2.2. 1-2-2 5. 12. 2. 14. 6. (. 1995). 2 6. 14 (. 16. 12. 8. 12. 16. 2007). 1-2-2. 5 (. 1995). 1-7. 12. (. ).

(12) 1. (Thakore and Holder, 1987) 16. (. 1998) 12. 14 16. 8. 160. (. 46. CH4. 2004). 1-8. 5.75H2O.

(13) 1. (. 2010) 1-2-3. 1-2-4 (. 2009). 80. 100m 1-9.

(14) 1. 1-2-3 (. ). 1-10.

(15) 1. 1-2-4. (. 1-11. ). (. ). (. 2009).

(16) 1 1.2.3. (. 2014). 1-2-5 (. 2013). ( ). bottom simulating reflector. BSR. BSR. 1-2-5. ( 1-12. 2013).

(17) 1 (. BSR. 1997). BSR 1-2-6. BSR. BSR 1-2-7. 1-2-6 BSR. (. 1-13. 1997).

(18) 1. 1-2-7 (. ). 1-14.

(19) 1 1-2-8. 1-2-8 (. ). 1-15.

(20) 1. (2009). X. CT. (Ta). (Tb). (Tc). (Td-e) 1-2-9. 1 40. 3 50m 40. 50%. 1-2-9. (. 1-16. 2009).

(21) 1 1-2-10. 1-2-11 Grain coating. cement. Pore filling. Load bearing. 1-2-10. Patchy. Contact 5. Contact cement Grain coating (Jeffery and Angus. (Pore filling bearing. 2005). ). (Load. ). Patchy. (Dai et al.,. 2012). 1-2-10. (Malone. 1-17. 1985).

(22) 1. 1-2-11 (Jeffery and Angus. 1-18. 2005. Dai et al., 2012. ).

(23) 1 1.2.4. (. ). (MH21-HYDERES). 2016. 12. (. ). 1-19. m3.

(24) 1 1.3. 1.3.1. Hyodo. (2013) 1-3-1. SMH. SMH=0%. SMH. 1-3-1. 1-20. (Hyodo et al.. 2013).

(25) 1. 1-3-2. -. 1-3-2. c. (2004). 3MPa. (2010). 1-21. (Hyodo et al.. 2013).

(26) 1 1-3-3. (2004). 1-3-4. 1-3-4. 1-3-3. 1. 1-22. 2. 3.

(27) 1. 1-3-3. -. 1-3-4. (. 2004). (. 1-23. 2004).

(28) 1 1.3.2. MH21. 2004 (JOGMEC). Pressure. 1-3-5. (. 1-24. 2010. ).

(29) 1 PTCS. Temperature Coring System (PTCS). 1-3-5. Aumann & Associates, Inc. Hybrid. Hydrate PCS. Pressure Coring System(Hybrid PCS). Pressure Core Analysis Transfer System (PCATs). (Schultheiss et al., 2011) (. 2014). P. S. (Yun. 2006). (Yoneda et al.. 2015a. 2015b). Yoneda. 1-3-6. Yoneda. 1-3-7. 1-3-6. X (Yoneda et al.. 2015a 1-25. ( ). ). (. ).

(30) 1. (a). (b). (c). 30 27 24 21 18 15 12 9 6 7 0. 1-3-7 (a). -. (b) (Yoneda et al.. (c) 2015a. ). 1-26.

(31) 1. 1-3-7(a). 1-3-6. 1-3-6. X. 1-27.

(32) 1 1.4. 1.4.1. 1-28.

(33) 1 1.4.2. 5. 1 2 3 4 5. 1. 2 4. 3. 4. 5 1-4-1. 1-29.

(34) 1. 1-4-1. 1-30.

(35) 1. Dai S., Santamarina J. C., Waite W. F. and Kneafsey T. J. : Hydrate morphology : Physical properties of sands with patchy hydrate saturation, Journal of Geophysical Research, Vol.117, B11205, 2012. Jeffery A. P. and Angus I. B. : A laboratory investigation into the seismic velocities of methane gas hydrate-bearing sand, Journal of Geophysical Research, Vol.110, B04102, 2005. JOGMEC http://www.jogmec.go.jp/news/release/news_02_000006.html (2016. 10. 31. ). Hyodo M., Yoneda J., Yoshimoto N., Nakata Y. : Mechanical and dissociation properties of methane hydrate-bearing sand in deep seabed, Soils and Foundations, Vol.53 (2), pp.299-314, 2013. Malone R. D.. Gas hydrates Topical Report. DOE/METC/SP-218. U.S. Department of Energy, April,. 1985. Schultheiss P., Holland M., Roberts J., Huggett, Q., Druce M. : PCATS: PRESSURE CORE ANALYSIS AND TRANSFER SYSTEM, Proc. 7th Int. Conf. on Gas Hydrate, pp.17-21, 2011. Thakore J. L. and Holder G. D. : Solid-Vapor Azeotropes in Hydratres in Hydrate-Forming Systems, Ind. Eng. Chem. Res., 26, p.462-469 1987. Yoneda J., Masui A., Konno Y., Jin Y., Egawa K., Kida M., Ito T., Nagao J., Tenma N. : Mechanical behavior of hydrate-bearing pressure-core sediments visualized under triaxial compression, Marine and Petroleum Geology, Vol.66, pp.451-459, 2015a. Yoneda J., Masui A., Konno Y., Jin Y., Egawa K., Kida M., Ito T., Nagao J., Tenma N. : Mechanical properties of hydrate-bearing turbidite reservoir in the first gas production test site of the Eastern Nankai Trough, Marine and Petroleum Geology, 66, pp.471-486, 2015b. Yun T. S., Narsilio G. A., Santamarina J. C., Ruppel C. : Instrumented pressure testing chamber for characterizing sediment cores recovered at in situ hydrostatic pressure, Vol.229, pp.285-293, 2006. : pp.287-289. 2007.. Vol.49 (10) 1. pp517-526. 1998.. -BSR-. , 26. Vol.510. pp.12-17. 1997.. 4. http://www.meti.go.jp/policy/energy_environment/energy_policy/energy2014/seisaku/pdf/ene_basi c_plan.pdf. (2016. 10. 31. ) 1-31.

(36) 1 2 (. ). 3 http://www.enecho.meti.go.jp/about/whitepaper/2014html/2-1-3.html. in situ CSMH-8. pp.17-19. (2016. 8. 4. ). 6. 2014.. Vol.118 (5). pp.899-912. 2009.. 2010. 1. MH. (. ). (HGES). 2013. Vol.41 (5). pp.57-68. -. 2007.. LNG. Business & Review. 39. Vol.60 (2). pp.365-366. 2012.. 2004.. pp.147-156, 1995. -. Vol.58. pp.11-30. pp.45-56. -. 2004. -. Vol.118 (1). pp.7-42. -. 2009. 2010. Journal of MMIJ 126 pp.-408-417. http://www.mh21japan.gr.jp/ (2016. 10. 31. ). 1. 20. 8. 2008. 2014. 1-32.

(37) 1 2014.. C. 66 (4). pp.742-756. 1-33. 2010..

(38) 2. 2. 2.1. 1. (. 2008) SMH. 50%. 80%. (. 40 2016). (Hyodo et al., 2013a. 2011). (Yoneda et al. 2015). 4. (2009). (. 2007 Matsushima et al., 2011 Tsumokos and Georgiannou 2010). 2-1.

(39) 2 2 3 4. 3. 2-2.

(40) 2 2.2. 2.2.1. 1). (Yoneda et al., 2013). 2-2-1. 2-2-2. 2-2-1. 2-3.

(41) 2. 2-2-2. 2-4.

(42) 2. 2-2-3. 2-5.

(43) 2. 2-2-1. 2-2-3 (. ). (. ). 160mm. 60mm. 80mm. 20MPa. 140mm. 75mm (. ). ( LED(. ). ). (. ). 2 25. 100000. 0.001%. (. ) (. ) (. (. ). ( (. ( 1000. 1. ( ( ). ). ). 200kN. 30mm(. ). ) 60mm(. 2-2-1. 2-6. ). ). ).

(44) 2 2. 2-2-4. 2-2-4. 2-7.

(45) 2 2.2.2. 2.2.2.1. 2 (2009). Ta Tb. Te. Tb. Tc Tc. 2-2-5 (. 2009) Tb. Tc. Tb 2-. 2-6. 2-2-2. 2-2-5. 2-8.

(46) 2. a) Toyoura sand. b) Glass beads. c) Tb. d) Tc 2-2-6. 2-2- 2. (. 2-9. %).

(47) 2 2.2.2.2. (Roundness coefficient. Rc). (Aspect. A r). ratio. (2-1). (2-2). L. A. b. (. ). a. 1. (2011) Tb. Tc 30. 7. 2-2-7. 8. 2-2-8. R5.5. 2-2-9 2-2-3. 1. 2-10.

(48) 2. 2-2-7. 7. 2-2-8. 8. 2-11.

(49) 2. 2-2-9. 5.5. 2-2-3. 2-12.

(50) 2 2.2.3. SMH. (1). (2-3) winitial(%). (. H. 0.912(g/cm3) ms(g). A CH4. 6H2O. CH4. 5.75H2O. CH4. 6H2O. A = 108/124 ×100 = 87.1(%) 6. SMH SMH 90% 80mm. 60mm. 160mm. SMH. VV. VMH. (2-2). (2-4). 5. (a) (b) (c). 12. (d). 0.2MPa. (. )5MPa (e). (. ). 5MPa (d). (e) (f). 1.3 2-13.

(51) 2 (g) (h) 1 0.1%/min (i). 3MPa. (j). PTV. 2-14.

(52) 2 2.2.4 PTV. (. 2008). Particle Tracking Velocimetry. PTV. 2. 2~4. PTV. 2-15.

(53) 2. 2-2- 10 PTV. PTV. (. 2011). 2-2-10. 2. pixel. mm. PTV. 5×5mm. 2-16.

(54) 2. 2-2-11. x. y. x. u x. x. (2-5). u: y. v y. y. (2-6). v: yx. u x. yx. v y. (2-7). v v. x. (2-8). y. max. 2 max. y. x. 2. (2-9). yx. 2-2-11. v max. 2-17.

(55) 2 2.2.5. 2-2-12. FE-SEM (2009) 2-2-13. 50%. MH. FE-SEM. C. 2-2-14. MH. MH. 2-2-12. 25 2-18. (. 2009. ).

(56) 2. 2-2-13. 200 (. 2009. 2-19. ).

(57) 2 2-2-14. MH. 2-2-14. 200 (. 2009. 2-20. ).

(58) 2 2.3. 2.3.1. 2-3-1. 4. 2.2.3 2-3-1. 2-3-2. 2-3-3. Tb. 2-3-5. c. 2-3-4. = 3MPa. Tb. Tc. 2-3-6 (a) (c). Tc. Tc. (b). (d). Tb 0.1MPa. 28 Tb. 2-3-7. 2-21. Tc. 3.

(59) 2. 2-22.

(60) 2. 2-3-1. 2-3-2. 2-3-3 Tb. 2-3-4 Tc 20. SMH=0%. '=3.0MPa. c. 16. 12. Toyoura sand. Glass beads Tb. Tc. 8. -5. 4. Toyoura sand. Glass beads. Tb. 0. 0. Tc 0. 2-3-5. 1. 2. 3. 4. 5. 6. Axial strain. 3MPa. 7 a. 8. (%). 9. -. 2-23. 10. 5.

(61) 2. 15. Rupture envelope line Toyoura sand S M H = 0% c d =0.45MPa,. d. =31.0. 10. 5MPa 3MPa 5. 1MPa. 0 0. 5. 10. 15. Principal stress. 20. ' (MPa). (a) 15. (b). Rupture envelope line T b S M H = 0% c d =0.28MPa,. d. =31.0. 10. 3MPa 5. 1MPa. 0 0. 5. 10. 15. Principal stress. 20. ' (MPa). (c). (d). 2-3-6. 15 Roundness cofficient Aspect ratio. 12. '=5.0MPa Host sand. c. 9. 6. '=3.0MPa Host sand. c. 3 '=1.0MPa Host sand. c. 0 0.5. 0.8. 1.1. 1.4. 1.7. Roundness coefficient & Aspect ratio. 2-3-7. 2-24. 2.0.

(62) 2 2.3.2. PTV 3MPa. 2%. 2-3-8. PTV. 2-3-9 a=2%. 50%. max. 3 Tb. Tc. Tb Tc. 2-25. Tc. Tb.

(63) 2. 2-3-8 a). b). c) Tb. 2-26. d) Tc. (. ).

(64) 2. 2-3-9 a). b). c) Tb d) Tc. 2-27. (. ).

(65) 2 2.4. 2.4.1. 2.3. 2-4-1 c. SMH. = 3MPa. 60%. 2-4-1 2-4-4. Tc. 2-4-2. ,. SMH. 40%. Tb. 2-4-3. (Hyodo et al., 2013a. a=0.83%. Tb. a=2.15%. Tc. a=3.77%. Tb. Tb. Tc. Yun. (2007) 50% Yun. 2-28. Miyazaki et al., 2011). a=1.91%. a. Tc.

(66) 2. 2-29.

(67) 2. 2-4-1. 2-4-2. 2-4-3 Tb. 2-4-4 Tc. 2-4-5. 2-30.

(68) 2. 2-4-5. 2-3-15 2-4-6. Tb. (. 2011). Tc. 2-4-7. E50. Tb. 2-4-8. 2-4-6. 2-4-7. 2-31. E50.

(69) 2 c. =1. 5MPa 2-4-9. 2-4-11. c. = 5MPa. 2-4-10. 2-4-12 cd = 0.45MPa cd = 0.6 cd = 0.1MPa. cd = 1.2MPa. d=31.0. d=36.5. d=28.0. d=28.0. 15. 13. SMH. 60%. 11. 9. 7. SMH=0% '=3.0MPa. c. 5 0. 5. 10. 15. Fines content (%) 2-4-8. 2-32. 20. 25.

(70) 2. 2-4-10. 2-4-9. 2-4-12. 2-4-11. 2-33.

(71) 2 2.4.2. 60% PTV. 2-4-13. PTV. 2-4-14 a=2%. (Desrues et al., 2004.). (Lade et al., 2014). ( Yoneda et al., 2016). 2-4-15 a=0.2%. Tb. Tc Tc. 2-4-14. a. = 4%. a. =8% a=. 8%. Tb. 2-34.

(72) 2. 2-4-13 a). b). c) Tb d) Tc. 2-35. (. ).

(73) 2. 2-4-14 a). b). c) Tb. 2-36. d) Tc. (. ).

(74) 2. 2-4-15. a). b) (. 2-37. c) Tb ). d) Tc.

(75) 2. 2-4-16. a). b). c) Tb. d) Tc. 2-4-17. a). b). c) Tb. d) Tc. 2-38.

(76) 2. 2.3.2. 2-4-16. 2-4-17. Cheng Weibull. (2003). Weibull. m. Ps (210) (1). c. Weibull. m. (1). (2-11). (2). Weibull a. Weibull Weibull. =2%. m. 2-4-18. 2-4-19. 2-4-18. m m. 2-4-20. Weibull. m. Weibull Tb Weibull. Tc. Weibull. m Tc Tb. 2-39.

(77) 2 6. Toyoura sand. a. =2.0% m. 4 2 0 -2 -4. y = 4.1949x r 2 = 0.8933. -6 -8 -2.0. -1.2. -0.4. 0.4. 1.2. 2.0. ln ( / c ) 2-4-18. a =2%. Weibull. 1.0 Toyoura sand. a. =2.0%. 0.8. 0.6. 0.4. 0.2. 0.0. 0. 1. 2. 3. Normalised maximum shear strain /. 2-4-19. 5. a =2%. Toyoura sand Glass beads Tb Tc. c. Weibull MH-Toyoura sand MH-Glass beads MH-T b MH-T c. 4. 3. 2. 1. 0 0. 2. 4. 6. 8. Axial strain 2-4-20. 10 a. (%). Weibull. 2-40. 12. 14.

(78) 2 2.4.3. Tc Yoneda (2013). 2-4-21 4-1. 2-4-22. 2-4-21. 2-4-22. 2-. 2-4-4. Tc (. 2-4-21. 2-4-22 Tc. 2-41. 1995).

(79) 2 2.4.4. 2-4-23. a=0.5%. Tb. 2. Tc 40%. 0%. 40%. 60%. Tb. 4-2-24 Contact cement. Grain coating Load bearing. Patchy 30%. Dai Load bearing. MH Patchy. 1500. Glass beads 1200. Toyoura sand. 900. Tb 600. 300. 0 0. Tc 10. 20. 30. 40. 50. 60. 70. Hydrate saturation (%) 2-4-23. E0.5. 2-42. 80.

(80) 2. 2-4-24. (Dai et al., 2012. 2-43. ).

(81) 2 2.5. Tb. Tc. (1). (2). (3). (4). (5) MH. E50. (6). (7). (8). (9) (10) Load bearing. Patchy. 2-44.

(82) 2. Cheng, Y., P., Nakata, Y., and Bolton, M., D. : Discrete element simulation of crushable soil, Geotechnique, Vol.53 (7), pp.633-641, 2003. Dai S., Santamarina J. C., Waite W. F. and Kneafsey T. J. : Hydrate morphology : Physical properties of sands with patchy hydrate saturation, Journal of Geophysical Research, Vol.117, B11205, 2012. Desrues, J., Viggiani, G. : Strain localization in sand: an overview of the experimental results obtained in Grenoble using stereophotogrammetry, Int. Journal for Numerical and Analyitical Methods in Geomechanics, Vol.28, pp.279-321, 2004 Hyodo, M., Nakata, Y., Yoshimoto, N., Yoneda, J. : Mechanical behavior of methane hydrate-supported sand. In: Proc. of the Int. Symposium on Geotechnical Engineering, Ground Improvement and Geosynthethics for Human security and Environmental Preservation, pp.195-208, 2007. Hyodo, M., Nakata, Y., Yoshimoto, N., Yoneda, J. : Shear strength of methane hydrate bearing sand and its deformation during dissociation of methane hydrate. In: Proc. of the 4th Int. Symposium on Deformation Characteristics of Geomaterials, pp.549-556, 2008. Hyodo, M., Yoneda, J., Yoshimoto, N., Nakata, Y. : Mechanical and dissociation properties of methane hydrate-bearing sand in deep seabed, Soils and Foundations, Vol.53 (2), pp.299-314, 2013a. Hyodo, M., Kajiyama, S., Yoshimoto, N., Nakata, Y. : Triaxial Behaviour of Methane Hydrate Bearing Sand, Proc. 10th Int. Conf. on Offshore and Polar Engineers, pp.126-131, 2013b. Lade, P., V., Trads, N. : The role of cementation in the behaviour of cemented soils, Geotechnical Research, Paper 14.00011, 2014. Matsushima, T., & Chang, C. S. : Quantitative evaluation of the effect of irregularly shaped particles in sheared granular assemblies, Granular Matter, Vol.13 (3), pp.269-276, 2011. Miyazaki, K., Masui, A., Sakamoto, Y., Aoki, K., Tenma, N., and Yamaguchi, T. : Triaxial compressive properties of artificial methane-hydrate-bearing sediment, Journal of Geophysical Research, Vol.116, B06102, 2011. Ord, A., Vardoulakis, I., Kajewsk, R. : Shear band formation in Gosford sandstone, Int. J. Rock Mech. Min. Sci. & Geomech. Abstr. Vol.28 (5) pp.397-409, 1991. Suzuki, M., Fujimoto, T., Taguchi, T. : Peak and residual strength characteristics of cement-treated soil cured under different consolidations, Soils and Foundations, Vol.54 (4), pp.687-698, 2014. Tsomokos A, Georgiannou VN. : Effect of grain shape and angularity on the undrained response of fine sands. Can Geotech J. Vol.47, pp.539-551, 2010. 2-45.

(83) 2 Waite, W. F., Santamarina, J. C., Cortes, D. D., Dugan, B. Espinoza, D. N., Germaine, J., Jang, J., Jung, J. W., Kneafsey, T. J., Shin, H., Soga, K., Winters, W. J., and Yun, T.-S. : Physical properties of hydrate-bearing sediments, Reviews of Geophysics, Vol.47, RG4003, 2009. Yoneda, J., Hyodo, M., Yoshimoto, N., Nakata, N., Kato, : A. Development of high-pressure low-temperature plane strain testing apparatus for methane hydrate-bearing sand, Soils and Foundations, Vol.53 (5), pp.774-783, 2013. Yoneda, J., Masui, A., Konno, Y., Jin Y., Egawa, K., Kida, M., Ito, T., Nagao, J., Tenma, N. : Mechanical properties of hydrate-bearing turbidite reservoir in the first gas production test site of the Eastern Nankai Trough, Marine and Petroleum Geology, Vol.66, pp.471-486, 2015. Yoneda, J., Jin, Y., Katagiri, J., Tenma, N. : Strengthening mechanism of cemented hydrate-bearing sand at microscales, Geophysical Research Letters, 43 (14), pp.7442-7450, 2016. Yun, T.S., Santamarina, J.C., Ruppel, C. : Mechanical properties of sand, silt, and clay containing tetrahydrofuran hydrate, Journal of geophysical research, 112, B04106, 2007. ,. ,. ,. , ,. ,. ,. , ,. , Vol.28 (1). pp.95-103. 2011.. ,. 46. , pp.377-378. 2011. 2.. (. Vol.175. 1). Vol.55 (4). pp.73-80. pp.62-68. 2007.. 1995.. 118 (5) : pp.899-912. 2009.. 2008. http://www.mh21japan.gr.jp/. 1. 20. 8. 2008. Vol.118 (5). pp.913-934. 2009. 2011. 88. 2011.. 2009. 2-46.

(84) 2. 2011.. 2-47.

(85) 3. 3. 3.1. 2013. 1 (. ). (. 2016). 1. 6 (. (. 2013). 2016). 2. Load bearing. (2016). Tc. 2 Tb. Tc. 3-1. Patchy.

(86) 3 2 3 4. 3-2.

(87) 3 3.2. 2. Tb. Tc. 3 2. 12. Dr. = 90%. 5 5MPa. 10MPa. c. 2. 10MPa. 3MPa. 0.1%/min 0.5MPa/min 3-2-1. 3-3. a.

(88) 3. 3-4.

(89) 3 3.3. SMH = 60.3% Tb. SMH = 57.3% 3-3-1. Tc. SMH = 41.3%. 3-3-3. Tb Tc. Tb. 3-3-4 3-3-5. Tc. Tb. 3-3-6. (a). (b). 3MPa. (d). (c) MH (e). (a). (d). MH. 12 10 8 6 4 2 0 8. Upper pore pressure Lower pore pressure. 0. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 0. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 0. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 6 4 2 0 40 30 20 10 0. Tim e t. 3-3-1. 3-5. (h ou r).

(90) 3 12 10 8 6 4 2 0 8. Upper pore pressure Lower pore pressure. 0. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 0. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 0 0. 1 1. 2 2. 3 3. 4 4. 7 8 7 8 (h ou r). 9 9. 10 10. 11 11. 12 12. 6 4 2 0 40 30 20 10 0. 3-3-2. 5 6 5 6 Tim e t. Tb. 12 10 8 6 4 2 0. Upper pore pressure Lower pore pressure. 0. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 0. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 0 00 0. 11. 22. 33. 44. 77 88 (h ou r). 99. 10 10. 11 11. 12 12. 8 6 4 2 0 40 30 20 10. 3-3-3. 55 66 Tim e t. Tc. 3-3-7 MH 3-3-8 Tb. 3-6.

(91) 3 5. Tb. Tc Tb. Tc 4MPa. 3MPa. 6. 6. (b). (c). 5. 5. (b). 4. 4. 3. 3. Failure envelope of MH bearing sand. 2. (e). Failure envelope of Host sand 1. (a). (a) 0 0. 5. 10. Mean principal stress. 15. ( '1 +. 0 0. 20. 5. 3-3-5. 6. (c) 5. (b) 4. (d). (e). 3. Failure envelope of MH bearing sand Failure envelope of Host sand. 1. (a) 0 0. 5. 10. Mean principal stress. 3-3-6. 15. ( '1 +. 10. Mean principal stress. ' 3 )/2 (MPa). 3-3-4. 2. (d). Failure envelope of MH bearing sand. 2. Failure envelope of Host sand. 1. (c). (d). (e). 20. ' 3 )/2 (MPa). Tc 3-7. Tb. 15. ( '1 +. 20. ' 3 )/2 (MPa).

(92) 3 12 11 10 9 8. 4. 7. 3. 6. 2. 5 1. 4 3. 0. 2. -1. 1. -2. 0 1. 2. 3. 4. 5. 6. 3-3-7. 7. 10. 9. 8. 7. 6. 5. 4. 3. 2. 1. 0. 8. -. 3-3-8. 1.0. 1.0 (e). End point of shearing (b). (b). (e). 0.5. 0.5. (d) (c). (c). Host sand. (a). (a). 0.0 0. 5. 10. Axial strain. a. 0.0 0. 15. 3-3-10 -. 1.0. (e). 0.5. Host sand (c) (d) (a). 5. 10. Axial strain. Tc. a. 15. (%). 3-8. 10 a. (%). Tb -. (b). 3-3-11. 5. Axial strain. (%). 3-3-9. 0.0 0. (d). Host sand. 15.

(93) 3 3.4. 3.4.1. 3-3-9 3-3-10. Tc. 3-3-11. Tb. 3MPa. 3MPa. (c). (d). 5. Stablity boundary at 5oC. 4. 3. Tb. 2 Tc. 1 Toyoura sand. 0 12. 11 10. 9. 8. 7. 6. 5. 4. 3. 2. Pore water pressure (MPa) 3-3-12. 3-9. 1. 0. 10MPa. Tb.

(94) 3. Tb. Tc. Tc 3-3-12 3MPa. Tb. Tb. 3-10. Tc. 4MPa.

(95) 3 3.4.2. MH PTV PTV. ax. 3-3-13. max=50%. Tb. Tc 6MPa. max=15%. PTV Weibull. m. Weibull c. B.P. =. 3MPa. 4MPa. 5MPa. 6MPa. 7MPa. 3-3-13. 3-11. 8MPa. 9MPa. 10MPa.

(96) 3 3-3-14. Weibull. m. 3-3-15 3-3-14. c. 9MPa. Weibull. Tb. m. 3-3-15. c. Tc Weibull. 3-3-14. 3-3-15. m. 9MPa. c. Tc. 3-3-13. 10MPa. Weibull c. 3-3-13 10MPa 3-3-15. Tb. c. Tc. 3-3-16 Weibull. m. 3 Tb. 3 Tb. Weibull. c. Tc. 8 7 6. 30 Toyoura sand Tb Tc. Toyoura sand Tb Tc. 25 20. 5 4. 15. 3. 10. 2 5. 1 0 0. 2. 4. 6. 8. 10. 0 0. 12. W ater pore pressure (MPa). 2. 4. 6. 8. 10. 12. W ater pore pressure (MPa). 3-3-14. 3-3-15. Weibull. c. 3-12.

(97) 3 c. 3-3-16. 2 Tc. 2-4-21. 2-4-22. Yoneda. Toyoura sand. Tb. (2013). Tb. Tc. 2.37mm. 1.68mm. 3-3-16. 3-13.

(98) 3 3.4. 3. (1). (2) Tb. Tc. (3). (4). (5). (6). 3MPa. 3-14.

(99) 3. Yoneda, J., Hyodo, M., Yoshimoto, N., Nakata, N., Kato, : A. Development of high-pressure low-temperature plane strain testing apparatus for methane hydrate-bearing sand, Soils and Foundations, Vol.53 (5), pp.774-783, 2013.. 2016. http://www.mh21japan.gr.jp/ (2016. COTHMA pp.6-12. 8. 2016.. 1 pp.77-78. 5. 2013.. 4. 2016. 2016.. 3-15. 11. 2. ).

(100) 4. 4. 4.1. 2. 3. 2. Load bearing Pore filling. 2. (. 3. DEM) 2. Load bearing. 2 3. DEM 4 5. 5. 4-1.

(101) 4. 4.2. 4.2.1. DEM. DEM. F=kn kn. F. n. (Catherine, 2011. n. 2014). (. 2015). DEM. 4.2.2. (1997). 1. 1. (4-1). (4-1). Y. t. (4-1). X. V (4-2). (4-2). X 1. t (4-3). (4-4) 4-2.

(102) 4 (4-3). (4-4). m. E. 1 E=K (4-2). (4-4). E=K. (4-5). (4-5). 3. m. (4-6). (4-6). r X. (4-7). (4-7). Vp. Vs. (4-8). (4-9). (4-8). (4-9). (4-5) (4-6) (4-7). kn. ks. (4-10) (4-11). (4-10). 4-3.

(103) 4 (4-11). (4-8). (4-9). (4-10). (4-11). (4-12). (4-13). ( ). 2 s=2.5g/cm. 3. (2004). =0.26. =0.25 (4-14). (4-12). (4-13). (4-15). (4-12). (4-13). E. (Catherine, 2011. 2014). Hertz-Mindlin. E E. Yang and Gu (2013) G0. Yang and Gu 4-2-1. 14). e. G0 0.559 E0. 4-4. (4-.

(104) 4. 4-2-1. G0. (Yang and Gu. 2013). 10 11. y = (5.41. 107) x 0.432. Yang and Gu, 2013 5. 10 2 10. 10 6. Mean principal stress (Pa) 4-2-2. E0. (Yang and Gu, 2013. 4-5. ).

(105) 4 (4-14). 4-2-2. E0. (4-15). (4-15). 4.2.3. 4.2.2 Vinod. (2015). DEM. 28. 1. 2mm. n=40% 30. 40. 80mm. 4074. 2/3 0.57 28 30. 40. 80mm. 1mm. 800. 80mm. 1600. 4-2-3. 4.3 1 4-2-4. 4-6. 0.

(106) 4. 4-2-3. (. 4-7. ). (. ).

(107) 4. 100 80 60 40 20 0. 0.01. 0.1. 1 Grain size (mm). 4-2-4 DEM. 4-8. 10.

(108) 4. 4.3. 4.3.1. DEM (2011). (. 2. DEM. ). (2015). DEM (. 2016) DEM (Jiang et al.,. 2014) 2010). MH. (Brugada et al.,. 4-3-1. DEM. 2 2. 3. DEM. 4-9.

(109) 4. 4-3-1. 4-10.

(110) 4 4.3.2. E ( 2008 Dai, 2012) EBP. ( 4-3-1. 1958). (4-15). (4-15). t. n. t=0. n. n=40% EBP. 4-3-1. (. 4-11. 1958).

(111) 4 (4-16). 0.9g/cm3. 28. 4.3.3. SMH DEM. SBP. (2016) 0.24mm. DEM. n=47.2%. 0.04mm. 28%. 1mm. 0.8mm. 0.9mm. SBP=25% SBP=20%. 4.3.4. pb_nb. (2013). (4-17). pb_sb. (4-18). (4-17). 4-12.

(112) 4. (4-18). A Dai. (2012) 4-3-2. SBP=20%. 20%. Load bearing. 0%. 0.85mm (2015). 4-3-2 pb_sb. pb_nb. 2.5MPa 4-3-2. 4-13.

(113) 4. 4-3-2 (Dai et al.. 15. 2012. ). Failure envelope line Gla ss be a d S M H. c d = 2.5MP a ,. 10. 3 MP a 5. 0 0. 40% d. =2 0 .0. 5 MP a. 1 MP a. 5. 10. Prin cip a l stre ss 4-3-3. 4-14. 15. ' (MP a). 20.

(114) 4. 4-3-2. 4-15.

(115) 4. 4.4. 4.4.1. DEM. 2. 1). 200kPa. 4.2.3. 2) 3). 200kPa. 200kPa 50kPa 3MPa. 4). 0.01m/s 1. 1. 10-6s. 10-8s. 4.4.2. 2. 4-4-1. 4-4-2. 4-4-3. 4-16. 0.5. 3.0MPa.

(116) 4 4-4-4. Yoneda. (2015). Yoneda. 3MPa. 4-4-5. 0%. 8%. 8%. 4-4-6. 20656. 8% 4-4-5. 4-4-7. 4-4-6. 1. 0. All G-B. 20% 1. 4-17. G-G.

(117) 4. 12. DEM Simulation. SMH=0% Experiment. 10 8. '=3.0MPa. c. 6 4. '=1.0MPa. 2. c. -5 0. -2 1. '=3.0MPa. c. 0. 3. 6. 9. 12. Axial strain. a. 15. (%). 4-4-1. 12. DEM Simulation. SMH=0%. 10 8. '=3.0MPa. c. 6 4. '=0.5MPa. c. '=1.0MPa. c. 2. -5 0. -2 1. '=3.0MPa. c. 0. 3. 6. 9. Axial strain 4-4-2 4-18. 12 a. (%). 15.

(118) 4. 12. DEM Simulation. MH bearing sand Host sand. 10 8. '=3.0MPa. c. 6 4. '=0.5MPa. c. '=1.0MPa. c. 2. -8 -6. 0. -4 -2 0. 0. 3. 6. 9. Axial strain. 12 a. 15 2. (%). 4-4-3. 8. DEM simulation Yoneda et al. (2015a) Yoneda et al. (2015b) Santamarina et al. (2015) Masui et al. (2007) Yoneda et al. (2010) Miyazaki et al. (2010) Empirical equation for natural core results Empirical equation for all results "Empirical equation for synthetic methane hydratebearing sand. (Miyazaki et al. (2010))". 7 6 5 4 3 2 1 0 0. 10. 20. 30. 40. 50. 60. 70. 80. Hydrate saturation (%). 4-4-4 (Yoneda et al., 2015a. 4-19. ).

(119) 4. 4-4-5. 4-4-6. 0%. 0%. (. (. ). 4-20. ). 8%. 8%. (. (. ). ).

(120) 4. 5. 4. 3. 2 All G-G G-B. 1. 0 0. 1. 2. 3. 4. Axial strain 4-4-7. 1. 4-21. 5 a. (%). 6. 7. 8.

(121) 4. 4.5. 4.5.1. 3. 1). k0=0.6. 2). 5. 4.4MPa(3 8.6MPa). 8.6MPa 3). 10kPa 8.6MPa. 0.01cm 0.01cm. 10MPa 4). 10kPa. 3MPa. 5). 4.5.2. 7MPa 4-5-1. K h=. 8.6MPa 10MPa. 4-22. 3. 1. 4-5-2.

(122) 4. 4-5-3. 15%. 2003 K0. (. 2010). Kh=0.60. 4-5-4. Kh=0.60 4-5-1. 3MPa 4-5- 4. Kh=0.60. Kh=0.60. 4-5-6. 4-5-7. Kh =0.43. Kh =0.60 (a). (b). (c) 10MPa). (f). ( (. (g). 8.6MPa) 3MPa). (g). (g (d). (e) 15%. Kh =0.43 Kh =0.60 Kh =0.60. 4-23. (a). (g. (.

(123) 4. 2. 1. 0 0.0. 0.5. Axial strain 4-5- 1. 1.0 a. (%). Kh =0.43. 2.0. 1.5. 1.0. 0.5. 0.0 0.80. 0.85. 0.90. Axial strain 4-5- 2. Kh =0.43. 4-24. 0.95 a. (%). 1.00.

(124) 4. 4-5- 3 15%. 4-25.

(125) 4. 2.0. 1.5. 1.0. 0.5. 0.0 0.0. 0.5. 1.0. Axial strain 4-5-4. 4-5-5. a. 1.5. (%). Kh =0.60. Kh =0.60. 0.25%. 4-26.

(126) 4. 5. 4. 3. 2 All G-G G-B. 1. 0. 4-5-6. (a). (b). Kh = 0.43. 1. (c). (d) (e) Time step. (f). (g). 5. 4. 3. 2 All G-G G-B. 1. 0. 4-5-7. (a). (b). Kh =0.60. 1. (c). (d) (e) Time step. 4-27. (f). (g').

(127) 4 4.6. 2. Load bearing. (1). (2). Kh = 0.43. (3) Kh = 0.60. (4). 1. Kh = 0.43. 4-28. Kh = 0.60.

(128) 4. Brugada J., Cheng Y. P. and Soga K.. Discrete element modelling of geomechanical behaviour of. methane hydrate soils with pore filling hydrate distribution, Granular Matter, pp.517 -525, 2010. Catherine O.. Particulate Discrete Element Modelling, CRC Press a member of the Taylor & Francis. Group., 2011.. (. ). 2014.. Dai S., Santamarina J. C., Waite W. F. and Kneafsey T. J. : Hydrate morphology : Physical properties of sands with patchy hydrate saturation, Journal of Geophysical Research, Vol.117, B11205, 2012. Jiang M., Chen H., Tapias M., Arroyo M. and Fang R. Study of mexhanical behavior and localization of methane hydrate bearing sediments with different saturations by a new DEM model, Computers and Geotechnics, pp.122-138, 2014. Vinod J. S., Hyodo M., Indraratna B. and Kajiyama S.. Shear behaviour of methane hydrate bearing. sand: DEM simulations, Proc. The Int. Symposium on Geomechanics from Micro to Macro (ISCambridge 2014), pp.355-359, 2014. Yang J. and Gu X. Q. Shear stiffness of granular material at small strains: does it depend on grain size? Geotechique. Vol.63 (2). pp.165-179. 2013.. Yoneda J., Masui A., Konno Y., Jin Y., Egawa K., Masato K., Ito T., Nagao J., Tenma. Mechanical. properties of hydrate-bearing turbidite reservoir in the first gas production test site of the Eastern Nankai Trough, Marine and Petroleum Geology, Vol.66 (2), pp.471-486, 2015.. 39. pp.391-392. 2004.. 67 pp.207-208. 2015.. 8. pp.92-93 2016.. Vol.8 (2) pp.221-237 2. DEM. 2013. MH Vol.8 pp.124-126. 67 4-29. 2011.. CD.

(129) 4 -603. 2012. 1997. Vol.17. pp.147-166. 1958.. 1. 20. 8. 2008. 3.. Vol.63 (5). pp.53-60. 2015.. 8 pp.22-25. 2016.. C. 66 (4). pp.742-756.. 4-30. 2010..

(130) 5. 5. 4. (1). MH. (2). Load bearing. Patchy. (3). (4) DEM. Kh = 0.6. Tb Tc. 5-1.

(131)