Influence of dilatancy on the frictional constitutive behavior of a saturated fault zone under a variety of drainage conditions

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

We use numerical simulations to investigate how fault zone dilatancy and pore fluid decompression influence fault strength and friction constitutive behavior. Dilatant hardening can change the frictional response and the effective critical stiffness, Kcr, which determines the transition from stable to unstable sliding in velocity weakening fault zones. We study the frictional shear strength response to numerical velocity stepping experiments and show that when the duration of pore fluid decompression is long compared to the time necessary for frictional evolution (as dictated by rate and state friction) both the effective critical slip distance (DC) and the effective shear strength direct effect (A) are increased. We investigate the role of fault zone permeability (k), dilatancy coefficient (ε), and the magnitude of shearing velocity of the fault zone (vlp) and compare results using the Dieterich and Ruina state evolution laws. Over the range from k = 10-15 to 10-21 m2, DC increases from 25 m to ∼2 mm and A increases from 0.15 to ∼5 MPa. We vary ε from 10-5 to 10-3 and the size of the velocity perturbation from 3X to 1000X and find large increases in the values of D C and A, which may lead to inhibition of unstable sliding. Our results indicate that spatial variations, with either depth or lateral extent, in ε and k could result in significant changes in the drainage state in fault zones. Such variation may lead to spatial variation of the nucleation and propagation of earthquakes based upon the drainage capabilities of the fault zone.

Original languageEnglish (US)
Article numberB10406
JournalJournal of Geophysical Research: Solid Earth
Volume116
Issue number10
DOIs
StatePublished - Oct 1 2011

Fingerprint

dilatancy
phreatic zone
drainage
Drainage
fault zone
pressure reduction
shear strength
Shear strength
sliding
friction
Friction
decompression
porosity
Fluids
fluids
spatial variation
shearing
Shearing
hardening
Hardening

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Geochemistry and Petrology
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science

Cite this

@article{e86f12fa244d4db9a3522e4c81059090,
title = "Influence of dilatancy on the frictional constitutive behavior of a saturated fault zone under a variety of drainage conditions",
abstract = "We use numerical simulations to investigate how fault zone dilatancy and pore fluid decompression influence fault strength and friction constitutive behavior. Dilatant hardening can change the frictional response and the effective critical stiffness, Kcr, which determines the transition from stable to unstable sliding in velocity weakening fault zones. We study the frictional shear strength response to numerical velocity stepping experiments and show that when the duration of pore fluid decompression is long compared to the time necessary for frictional evolution (as dictated by rate and state friction) both the effective critical slip distance (DC) and the effective shear strength direct effect (A) are increased. We investigate the role of fault zone permeability (k), dilatancy coefficient (ε), and the magnitude of shearing velocity of the fault zone (vlp) and compare results using the Dieterich and Ruina state evolution laws. Over the range from k = 10-15 to 10-21 m2, DC increases from 25 m to ∼2 mm and A increases from 0.15 to ∼5 MPa. We vary ε from 10-5 to 10-3 and the size of the velocity perturbation from 3X to 1000X and find large increases in the values of D C and A, which may lead to inhibition of unstable sliding. Our results indicate that spatial variations, with either depth or lateral extent, in ε and k could result in significant changes in the drainage state in fault zones. Such variation may lead to spatial variation of the nucleation and propagation of earthquakes based upon the drainage capabilities of the fault zone.",
author = "Jon Samuelson and Derek Elsworth and Chris Marone",
year = "2011",
month = "10",
day = "1",
doi = "10.1029/2011JB008556",
language = "English (US)",
volume = "116",
journal = "Journal of Geophysical Research",
issn = "0148-0227",
publisher = "American Geophysical Union",
number = "10",

}

TY - JOUR

T1 - Influence of dilatancy on the frictional constitutive behavior of a saturated fault zone under a variety of drainage conditions

AU - Samuelson, Jon

AU - Elsworth, Derek

AU - Marone, Chris

PY - 2011/10/1

Y1 - 2011/10/1

N2 - We use numerical simulations to investigate how fault zone dilatancy and pore fluid decompression influence fault strength and friction constitutive behavior. Dilatant hardening can change the frictional response and the effective critical stiffness, Kcr, which determines the transition from stable to unstable sliding in velocity weakening fault zones. We study the frictional shear strength response to numerical velocity stepping experiments and show that when the duration of pore fluid decompression is long compared to the time necessary for frictional evolution (as dictated by rate and state friction) both the effective critical slip distance (DC) and the effective shear strength direct effect (A) are increased. We investigate the role of fault zone permeability (k), dilatancy coefficient (ε), and the magnitude of shearing velocity of the fault zone (vlp) and compare results using the Dieterich and Ruina state evolution laws. Over the range from k = 10-15 to 10-21 m2, DC increases from 25 m to ∼2 mm and A increases from 0.15 to ∼5 MPa. We vary ε from 10-5 to 10-3 and the size of the velocity perturbation from 3X to 1000X and find large increases in the values of D C and A, which may lead to inhibition of unstable sliding. Our results indicate that spatial variations, with either depth or lateral extent, in ε and k could result in significant changes in the drainage state in fault zones. Such variation may lead to spatial variation of the nucleation and propagation of earthquakes based upon the drainage capabilities of the fault zone.

AB - We use numerical simulations to investigate how fault zone dilatancy and pore fluid decompression influence fault strength and friction constitutive behavior. Dilatant hardening can change the frictional response and the effective critical stiffness, Kcr, which determines the transition from stable to unstable sliding in velocity weakening fault zones. We study the frictional shear strength response to numerical velocity stepping experiments and show that when the duration of pore fluid decompression is long compared to the time necessary for frictional evolution (as dictated by rate and state friction) both the effective critical slip distance (DC) and the effective shear strength direct effect (A) are increased. We investigate the role of fault zone permeability (k), dilatancy coefficient (ε), and the magnitude of shearing velocity of the fault zone (vlp) and compare results using the Dieterich and Ruina state evolution laws. Over the range from k = 10-15 to 10-21 m2, DC increases from 25 m to ∼2 mm and A increases from 0.15 to ∼5 MPa. We vary ε from 10-5 to 10-3 and the size of the velocity perturbation from 3X to 1000X and find large increases in the values of D C and A, which may lead to inhibition of unstable sliding. Our results indicate that spatial variations, with either depth or lateral extent, in ε and k could result in significant changes in the drainage state in fault zones. Such variation may lead to spatial variation of the nucleation and propagation of earthquakes based upon the drainage capabilities of the fault zone.

UR - http://www.scopus.com/inward/record.url?scp=80055024255&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80055024255&partnerID=8YFLogxK

U2 - 10.1029/2011JB008556

DO - 10.1029/2011JB008556

M3 - Article

AN - SCOPUS:80055024255

VL - 116

JO - Journal of Geophysical Research

JF - Journal of Geophysical Research

SN - 0148-0227

IS - 10

M1 - B10406

ER -