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Numerical simulation
of failed zone propagation process and anomalies related to
the released energy during a compressive jog intersection
Xue-Bin Wang, Jin Ma and Li-Qiang Liu |
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Vol. 5 (2010), No. 6, 1007–1022
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Abstract |
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A compressive echelon fault structure is modeled using an explicit finite difference code (FLAC). The Weibull distribution is used to reflect the heterogeneity of elemental parameters. The released elastic strain energies due to shear and tensile failures are calculated using FISH functions. We examine the failed zone propagation process and the temporal and spatial distribution of the released strain energy, emphasizing those during the jog intersection. A specimen including two parallel faults with an overlap is divided into square elements. Rock and faults are considered as nonhomogeneous materials with uncorrelated mechanical parameters (elastic modulus, tensile strength and cohesion). A Mohr–Coulomb criterion with tension cut-off and a post-peak brittle law are used. During the jog intersection, high values of released tensile strain energy are found at wing failure zones and at fault tips, while high values of released shear strain energy are found at faults. Despite the jog intersection, the released strain energy in the jog is not high. We also introduce a quantity describing the slope of the curve connecting the number of failed elements and the energy released. This is similar to the quantity found in the literature, but is expressed in units of J. Before the jog intersection, some anomalies associated with shear sliding of rock blocks along faults can be observed from the number of failed elements (in shear, in tension and in either), the accumulated released strain energy due to shear and tensile failures, the strain energy release rates in shear and in tension, and the value of . As deformation proceeds, the evolution of is calculated according to two kinds of the released energy: total energy due to shear and tensile failures and shear strain energy. The two exhibit similar behavior, suggesting that the released strain energy in shear is much higher than in tension. |
Keywords
compressive echelon fault structure, jog intersection,
failed zone, released strain energy, heterogeneity, shear
failure
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Milestones
Received: 22 July 2010
Revised: 13 October 2010
Accepted: 14 October 2010
Published: 1 January 2011
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Authors |
| Xue-Bin Wang | |
| State Key Laboratory of Earthquake
Dynamics Institute of Geology China Earthquake Administration Beijing, 100029 China |
College of Mechanics and
Engineering Liaoning Technical University Fuxin, 123000 China |
| Jin Ma | |
| State Key Laboratory of Earthquake
Dynamics Institute of Geology China Earthquake Administration Beijing, 100029 China |
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| Li-Qiang Liu | |
| State Key Laboratory of Earthquake
Dynamics Institute of Geology China Earthquake Administration Beijing, 100029 China |
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