Numerical simulation of hydro-mechanical constraints on the geometry of a critically tapered accretionary wedge

다국어 초록 (Multilingual Abstract)

A critically tapered active accretionary wedge was simulated using a numerical analysis of plastic slip-line theory to understand the mechanics of morphologic evolution. The concept of critical state soil mechanics was applied to describe the entire wedge area overlying a basal décollement fault. Presuming a condition of two-dimensional plane strain along the compressional direction, we obtained the numerical solution of conjugate plastic slip lines at a critical state of stress defined by the Coulomb yield criterion. The velocity vectors were obtained by applying the associate flow rule with the boundary conditions at the upper surface of the wedge. Finally, the detachment was determined from the effective stress condition inside the wedge and the sliding friction coefficient along the fault. Our numerical simulations demonstrate that the morphology of a critically tapered wedge is dependent on the frictional strengths of both the wedge materials and the basal fault. The critical taper angle decreases with increasing internal friction angle and decreasing basal friction coefficient. The results also revealed that the pore pressure controls the morphology of the accretionary wedge for cohesive sediments but not for non-cohesive materials. The effect of pore pressure on the morphology of a critically tapered accretionary wedge becomes more significant as the cohesion increases. Assuming that the cohesion is very low, we could infer the ranges of strengths that most observed wedge geometry data have 0.3–0.6 for the basal friction coefficient and ~35–45° for the internal friction angle of the wedge materials.

참고문헌 (Reference)

1 Martin, C. M., "User guide for ABC – analysis of bearing capacity, Ver. 1" University of Oxford 81-, 2004

2 Han, R., "Ultralow friction of carbonate faults caused by thermal decomposition" 316 : 878-881, 2007

3 Terzaghi, K., "Theoretical Soil Mechanics" John Wiley & Sons 510-, 1954

4 Martin, C. D., "The strength of massive Lac du Bonnet Granite around underground openings" University of Manitoba 1993

5 Gibson, R.E., "The progress of consolidation in a clay layer increasing in thickness with time" 8 : 171-182, 1958

6 Elliott, D., "The energy balance and deformation mechanisms of thrust sheets" 283 : 289-312, 1976

7 Breen, N. A., "The effects of fluid escape on accretionary wedges 1. Variable porosity and wedge convexity" 97 : 9265-9275, 1992

8 A. W. SKEMPTON, "The consolidation of clays by gravitational compaction" Geological Society of London 125 (125): 373-411, 1969

9 Elliott, D., "The Motion of the thrust sheets" 81 : 949-963, 1979

10 Davis, D. M., "The Mechanics of Thrust Faults: A Sand Box Model" Princeton University 1978

11 Hill, R., "The Mathematical Theory of Plasticity" Clarendon Press 355-, 1950

12 Seely, D. R., "The Geology of Continental Margins" Springer-Verlag 249-260, 1974

13 R. Mourgues, "The Coulomb critical taper theory applied to gravitational instabilities" American Geophysical Union (AGU) 119 (119): 754-765, 2014

14 Roeder, D., "Studies in Geology 2" University of Tennessee 25-, 1978

15 Bally, A. W., "Structure, seismic, data and orogenic evolution of southern Canadian Rocky Mountains" 14 : 337-381, 1966

16 Terzaghi, K., "Stresses in rock around cavities" 3 : 57-99, 1952

17 Lee, H. J., "Strength Testing of Marine Sediments: Laboratory and In‐Situ Measurements. ASTM STP 883" American Society for testing and materials 181-250, 1985

18 Sokolovskiĭ, V. V., "Statics of Granular Media" Pergamon 270-, 1965

19 Y M Cheng, "Solution of the bearing capacity problem by the slip line method" Canadian Science Publishing 42 (42): 1232-1241, 2005

20 Lambe, T. W., "Soil Mechanics" John Willey and Sons 553-, 1969

21 Wood, D. M., "Soil Behaviour and Critical State Soil Mechanics" Cambridge University Press 462-, 1990

22 Tapponnier, P., "Slip-line field theory and largescale continental tectonics" 264 : 319-324, 1976

23 Hubbert, M. K., "Role of fluid pressure in mechanics of overthrust faulting" 70 : 115-166, 1959

24 Peter B. Flemings, "Pressure and Stress Prediction in the Nankai Accretionary Prism: A Critical State Soil Mechanics Porosity-Based Approach" American Geophysical Union (AGU) 123 (123): 1089-1115, 2018

25 Stump, B. B., "Pressure Regimes in Sedimentary Basins and Their Prediction" American Association of Petroleum Geologists Memoirs 131-144, 2002

26 Song, I., "Polyaxial strength criteria and their use in estimating in situ stress magnitudes from borehole breakout dimensions" 34 : 116-, 1997

27 Yu, H. -S., "Plasticity and Geotechnics" Springer 522-, 2006

28 Davis, R. O., "Plasticity and Geomechanics" Cambridge University Press 287-, 2002

29 Rice, J. R., "Plane strain slip line theory for anisotropic rigid/plastic materials" 21 : 63-74, 1973

30 Screaton, E. J., "Permeabilities, fluid pressures, and flow rates in the Barbados ridge complex" 95 : 8997-9007, 1990

31 Zhao, W. -L., "Origin of convex accretionary wedges : evidence from Barbados" 91 : 10246-10258, 1986

32 Beck, R. H., "Oceans, new frontier in exploration" 58 : 376-395, 1974

33 Burden, R. L., "Numerical Analysis" Brooks/Cole 872-, 2011

34 Dahlen, F. A., "Noncohesive critical Coulomb wedges : an exact solution" 89 : 10125-10133, 1984

35 Gutscher, M. -A., "Non-Coulomb wedges, wrong-way thrusting, and natural hazards in Cascadia" 29 : 379-382, 2001

36 Stockmal, G. S., "Modeling of large-scale accretionary wedge deformation" 88 : 8271-8287, 1983

37 Chapple, W. M., "Mechanics of thin-skinned fold-and thrust belts" 89 : 1189-1198, 1978

38 Dahlen, F. A., "Mechanics of fold-and thrust belts and accretionary wedges : cohesive Coulomb theory" 89 : 10087-10101, 1984

39 Davis, D. M., "Mechanics of fold-and thrust belts and accretionary wedges" 88 : 1153-1172, 1983

40 B. Gao, "Mechanics of Fold‐and‐Thrust Belts Based on Geomechanical Modeling" American Geophysical Union (AGU) 123 (123): 4454-4474, 2018

41 Song, I., "Mechanical characterization of slope sediments : constraints on in situ stress and pore pressure near the tip of the megasplay fault in the Nankai accretionary complex" 12 : Q0-, 2011

42 Goldsby, D. L., "Low frictional strength of quartz rocks at subseismic slip rates" 29 : 25-21, 2002

43 Bethke, C.M., "Linear and nonlinear solution for one‐dimensional compaction flow in sedimentary basin" 24 : 461-467, 1988

44 Marone, C., "Laboratory-derived friction laws and their application to seismic faulting" 26 : 643-696, 1998

45 Goodman, R. E., "Introduction to Rock Mechanics" John Wiley & Sons 562-, 1989

46 Saffer, D. M., "Hydrologic controls on the mechanics and morphology of accretionary wedges and thrust belts" 30 : 271-274, 2002

47 Saffer, D. M., "Hydrogeology and mechanics of subduction zone forearcs : fluid flow and pore pressure" 39 : 157-118, 2011

48 Skarbek, R. M., "Heterogeneous Coulomb wedges : influence of fluid pressure, porosity, and application to the Hikurangi subduction margin, New Zealand" 122 : 1585-1613, 2017

49 Westbrook, G. K., "Geophysical evidence for the role of fluids in accretionary wedge tectonics" 335 : 227-224, 1991

50 Turcotte, D., "Geodynamics" Cambridge University Press 623-, 2014

51 Biot, M. A., "General theory of three-dimensional consolidation" 12 : 155-164, 1941

52 Jaeger, J. C., "Fundamentals of Rock Mechanics" Chapman and Hall 593-, 1979

53 Sone, H., "Frictional resistance of faults during accelerating and decelerating earthquake slip" 2 : 705-708, 2009

54 Krenk, S., "Friction, dilation, and plastic flow potential" Physics of Dry Granular Media 255-260, 1997

55 Byerlee, J., "Friction of rocks" 116 : 615-626, 1978

56 G. Di Toro, "Fault lubrication during earthquakes" Springer Science and Business Media LLC 471 (471): 494-498, 2011

57 Chang, C., "Empirical relations between rock strength and physical properties in sedimentary rocks" 51 : 223-237, 2006

58 Morgan, J.K., "Ductile strains in clay‐rich sediments from Hole 808C : preliminary results using X‐ray pole figure goniometry" 131 : 141-155, 1993

59 Dugan, B., "Data report: strength characteristics of sediments from IODP Expedition 308, Site U1322 and U1324" 308 : 2009

60 Tan, B., "Data report: consolidation and strength characteristics of sediments from ODP Site 1244, Hydrate Ridge, Cascadia continental margin" 204 : 1-148, 1244

61 Michel, G. W., "Crustal motion and block behaviour in SE-Asia from GPS measurements" 187 : 239-244, 2001

62 Dahlen, F. A., "Critical taper model of fold-and-thrust belts and accretionary wedge" 18 : 55-99, 1990

63 Lallemand, S. E., "Coulomb theory applied to accretionary and nonaccretionary wedges : possible causes for tectonic erosion and/or frontal accretion" 99 : 12033-12055, 1994

64 Sagiya, T., "Coseismic slip resolution along a plate boundary megathrust : the Nankai Trough, southwest Japan" 104 : 1111-1129, 1999

65 Suzuki, K., "Control factor of K0‐value, which indicates initial stress conditions and physical properties of sediments" 2003

66 Saffer, D. M., "Comparison of smectite-and illiterich gouge frictional properties : application to the updip limit of the seismogenic zone along subduction megathrusts" 215 : 219-223, 2003

67 Lehner, F. K., "Comments on"noncohesive critical Coulomb wedges : an exact solution by F. A. Dahlen" 91 : 793-796, 1986

68 Fletcher, R. C., "Approximate analytical solutions for a cohesive fold-and-thrust wedge : some results for lateral variation in wedge properties and for finite wedge angle" 94 : 10347-10354, 1989

69 Pierre Henry, "Anisotropy of electrical conductivity record of initial strain at the toe of the Nankai accretionary wedge" American Geophysical Union (AGU) 108 (108): 2003

70 Demian M. Saffer, "An evaluation of factors influencing pore pressure in accretionary complexes: Implications for taper angle and wedge mechanics" American Geophysical Union (AGU) 111 (111): 2006

71 Spencer, A. J. M., "A theory of the kinematics of ideal soils under plane strain conditions" 12 : 337-351, 1964

72 Robert L. Jackson, "A Solution of Rigid–Perfectly Plastic Deep Spherical Indentation Based on Slip-Line Theory" Springer Science and Business Media LLC 58 (58): 2015