27 June 2015GLG510 Advanced Structural Geology Faults and stress.

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April 21, 2023 GLG510 Advanced Structural Geology

Faults and stress

Relationship between traction and stress

yx = yx

Faults and stress: traction and stress

Mohr CircleGraphical construction that lets us visualize the relationship between the principal stresses and tractions on a boundary (like a fault).

measured positive clockwise from 1 direction clockwise to plane of interest2 measure positive clockwise from –n direction on Mohr circle

Equations of the Mohr Circle (also “Cauchy’s equations”)

= s-Davis and Reynolds

-Engelder, 1993, Stress regimes in the lithosphere, Princeton Univ. Press

Pollard and Fletcher

Coulomb Law of Failure

Coulomb equation c = c + tan n

Wherec = critical shear stress required for faulting (shear strength)c = cohesive strengthtan = coefficient of internal friction =

April 21, 2023 GLG510 Advanced Structural Geology-D+R

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