Seismic deformation analysis of Embankment DAMS: A comparison between simplified and non-linear numerical methods

The principal seismic concern for design of an embankment dam is the development of displacement patterns that could lead to failure and uncontrolled release of water and/or tailings in the event of a significant earthquake. The prediction of such movements is dependent on the accuracy and complexity of the analysis procedure used. Despite their limitations, equivalent linear approaches coupled with simplified deformation analysis methods (such as Newmark) have been widely used to model seismic nonlinear behaviour of soils. The most commonly used computer code for this purpose is SHAKE which works in a frequency domain and has been shown by previous studies to not necessarily predict a conservative estimate of dynamic response and deformations. In order to illustrate how variations in the adopted analysis method could affect the computed deformations a number of case studies are discussed and the predicted earthquake induced deformations by various methods ranging from empirical and Newmark based schemes to nonlinear numerical analyses, are compared