Stabilité des pentes sous-marines de l’atoll de Mururoa sous sollicitations dynamiques

Abstract

Stability of the fore-reef of Mururoa atoll under dynamic loading AbstractThe stability of the ocean slopes of the Muroroa atoll has been monitored throughout the operation of the French Centre d'Expérimentation du Pacifique. The Northern zone of the corallian rim has been instrumented in the early eighties when the reactivation of some border cracks was verified. The soft chalky limestone present in the slope formations caused these natural border cracks. The dynamic loads resulting from the tests initiated a creeping motion of the chalky limestones. The analysis in laboratory of the mechanical properties of these rocks, the creation of analog scale models and numerical simulations contribued to the understanding of the slope materials behavior during more than 80 tests. The trend to compacting mechanical behaviour of the chalky limestones indicates that the long term evolution of the motion is probably toward stabilization.