Normal fault rupture propagation through earth dams: centrifuge and numerical modelling

Permanent fault dislocation is a significant geological phenomenon that can cause severe damage to earth dams and must be considered in seismic design. In this study, to address existing uncertainties and close current knowledge gaps, a series of centrifuge experiments at an acceleration of n = 60 g, followed by finite element analyses, were performed to evaluate the fault rupture path in earth dams with clayey cores constructed on alluvial foundation layers. During faulting, the deformation pattern and the pure vertical movements at various locations were monitored. The results indicate that earth dams subjected to normal faulting may experience substantial damage, ranging from considerable deformation in the shell to transverse cracking in the core. Moreover, reducing the thickness of the alluvial foundation layer intensifies the induced damage. The presence of a cutoff wall at the centre of the core further amplified the damage observed in this study’s configurations. Although centrifuge modelling involves limitations such as height constraints and the absence of reservoir water, the experiments provide valuable insights about dam’s behaviour during fault rupture.