Thrust faults

Thrust fault mechanics

With Harsha Bhat (ENS Paris), Kurama Okubo (Harvard) and Esteban Rougier (Los Alamos National Laboratory)

Thrust faults are commonly known to produce larger slip, damage and ground acceleration as the rupture approaches the free surface. Preliminary work from Gabuchian et al. [2017] supports a novel solution which simply built on the natural asymmetry of
the geometry of reverse faults. Combining numerical and experimental simulations, they showed that, when propagating up dip toward the free surface, the earthquake rupture induces large deformation, especially rotation of the hanging wall, the region above the fault.

In this work, we take advantage of new numerical algorithms for dynamic modeling of earthquake rupture to describe more carefully the physical mechanisms behind the free surface effect. We use enhanced numerical algorithms for earthquake rupture recently developed by the Los Alamos National Laboratory. The numerical method behind these algorithms is called combined finite-discrete element method (FDEM) and can effectively reproduce earthquake rupture nucleation and propagation.