Effects of Dam Construction Levels on displacement and Shear band propagation due to fault movement

Field evidence from recent earthquakes has shown that some structures can be designed to resist major surface dislocations, like fault ruptures within earthquake; For instance extra design criteria and new specifications must be taken into account especially in large structures like embankment dams constructed on active faults, which are being flourished in our country .In the present study, the rupture (shear band) propagation through an embankment and linked uniform soil cover due to normal fault rupture in the underlying bedrock is simulated numerically, for different dips and heights of embankment .The numerical predictions are subsequently interpreted with emphasis on the evolution of ground surface displacement as a function of the fault dip angle β, the imposed fault movement .A finite difference method based software, FLAC, was adopted for the numerical analysis .A two dimensional model for simulating the normal faulting is setup, in which isotropic strain-softening model is used to simulate shear strain propagation in the continuous media .After calibration of modeling; shear band propagation in alluvium and embankment are investigated during period of construction; results show that there is a critical deformation zone, in which embankment construction changes its width .In the second parts of studies, effect of embankment construction stage is explored in the shear band formation; initial outcomes show that shear band direction in the dam body is not linear and is sensitive to embankment construction stage

Keywords:

Fault rupture , Embankment dam , Alluvial foundation , Shear band