Structural control of rupture dynamics : simulation issues and tsunami hazard application
IPGP - Îlot Cuvier
Séminaires de Sismologie
Università di Napoli Federico II
Earthquake ruptures occurring inland or along subduction zones are driven by normal and tangential stress coupling owing to the geometry of the fault plane, eventually embedded between dissimilar materials and to the interaction with waves reflected from Earth surface as the rupture propagates upward in shallow regions. Using the Spectral Element Method with a non-smooth contact formulation, the talk will revisit the problem of in-plane interface rupture propagation between dissimilar elastic media, in the case of slip-weakening friction. The classical Prakash-Clifton regularization, making the problem well-posed is investigated through a parametric study. As a response to a missing length scale, a new non-local regularization approach is proposed, associated to the actual size of the cohesive zone. Numerical results are shown to be consistent with mathematical modeling of dynamic interface rupture propagation with a process zone ahead of the rupture front. Interaction of the rupture with free-surface for different incidence angles is investigated, in terms of stress changes induced by waves reflected from the free surface, in the generation of large interface slip, slip waves and opening effects. Finally, the effect of dynamic rupture propagation in complex subduction zones is incorporated in tsunami scenario evaluation through a modification of stochastic slip models. The influence on tsunami hazard is discussed.