 |
| Titel |
Deterministic chaos in frictional wedges. |
| VerfasserIn |
Baptiste Mary, Bertrand Maillot, Yves M. Leroy |
| Konferenz |
EGU General Assembly 2013
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250074556
|
|
|
|
|
|
| Zusammenfassung |
| A triangular wedge, composed of a frictional material such as sand, and accreting additional
material at its front, is the classical prototype for accretionary wedges and fold-and-thrust
belts. The Sequential Limit Analysis method is applied to capture the internal deformation to
these structures resulting from a large number of faulting events during compression. The
method combines the application of the kinematic approach of limit analysis to predict the
optimum thrust-fold and a set of geometrical rules to update the geometry accordingly, at
each increment of shortening. It is shown that the topography remains planar to first order
with an average slope predicted by the critical Coulomb wedge theory. Failure by faulting
occurs anywhere within the wedge at criticality and its exact position is sensitive to
topographic perturbations resulting from the deformation history. The convergence analysis
in terms of the shortening increments and of the topography discretisation reveals
that the timing and the position of a single faulting event cannot be predicted. The
convergence is achieved nevertheless in terms of the statistics of the distribution
of the faulting events throughout the structure and during the entire deformation
history. These two convergence properties plus the perturbation sensitivity justify the
claim that these compressed frictional wedges are imperfection sensitive, chaotic
systems. This fundamental system has to be understood before considering the
influence of softening on activated ramps and of erosion which are also discussed. |
|
|
|
|
|
|