Steady shear and thermal run-away in clayey gouges

In the present paper we study the thermo-viscoplastic coupling in clayey fault-gouges under shear. It is shown that steady shear for a strain-rate hardening/thermally softening clay is only then possible, if the ambient temperature is less than some well-defined critical value. Past this critical temperature the balance between the two antagonistic mechanisms of viscous strengthening and thermal softening cannot be sustained and may result in dynamic (catastrophic) shear deformation.

[1]  B. Voight,et al.  FRICTIONAL HEAT AND STRENGTH LOSS IN SOME RAPID LANDSLIDES , 1982 .

[2]  James K. Mitchell,et al.  INFLUENCE OF TEMPERATURE VARIATIONS ON SOIL BEHAVIOR , 1968 .

[3]  J. Tchalenko,et al.  Microscopic Structures in Kaolin Subjected to Direct Shear , 1967 .

[4]  Gaston H. Gonnet,et al.  On the LambertW function , 1996, Adv. Comput. Math..

[5]  R. Nova.  Soil models as a basis for modelling the behaviour of geophysical materials , 1986 .

[6]  A. Bishop,et al.  The influence of high pore-water pressure on the strength of cohesionless soils , 1977, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[7]  Fusao Oka,et al.  CONSTITUTIVE EQUATIONS FOR NORMALLY CONSOLIDATED CLAY BASED ON ELASTO-VISCOPLASTICITY , 1982 .

[8]  James K. Mitchell,et al.  GENERAL STRESS-STRAIN-TIME FUNCTION FOR SOILS , 1968 .

[9]  I. Vardoulakis,et al.  Bifurcation Analysis in Geomechanics , 1995 .

[10]  Ioannis Vardoulakis,et al.  A Biaxial Apparatus for Testing Soils , 1990 .

[11]  J. N. Hutchinson,et al.  Ring shear tests on soil from the Vaiont landslide slip surface , 1999 .

[12]  I. Vardoulakis.  Dynamic thermo-poro-mechanical analysis of catastrophic landslides , 2002 .

[13]  L. Smith,et al.  Pore-fluid pressures and frictional heating on a fault surface , 1984 .

[14]  Tomasz Hueckel,et al.  Thermoplasticity of Saturated Soils and Shales: Constitutive Equations , 1990 .

[15]  Nabil Sultan,et al.  A thermomechanical model for saturated clays , 2000 .

[16]  Lyesse Laloui,et al.  A thermo-viscoplastic constitutive model for clays , 1997 .

[17]  Ioannis Vardoulakis,et al.  Catastrophic landslides due to frictional heating of the failure plane , 2000 .

[18]  J. Watterson.  Fault dimensions, displacements and growth , 1986 .

[19]  Donald W. Taylor,et al.  Fundamentals of soil mechanics , 1948 .

[20]  D. A. Barry,et al.  Analytical approximations for real values of the Lambert W -function , 2000 .

[21]  A J Hendron,et al.  The Vaiont Slide: A Geotechnical Analysis Based on New Geologic Observations of the Failure Surface, Volume 1: Main Text , 1985 .

[22]  K. Otsuki.  On the relationship between the width of shear zone and the displacement along fault. , 1978 .

[23]  I. Gruntfest,et al.  Thermal Feedback in Liquid Flow; Plane Shear at Constant Stress , 1963 .