Dynamic characterization of tailing dam using fully coupled dynamic analysis with different boundary conditions — a case study.

The seismic response analysis of a tailing dam is studied using a fully coupled effective stress approach in conjunction with an advanced multi yield surface plastic constitutive model for tailing material. Strain controlled static and cyclic triaxial tests were carried out to obtain the constitutive model for the tailing material. The tailing materials were collected from the Rampura Agucha tailing dam (Rajasthan State, India). A 2D nonlinear finite element (FE) model was then developed using different boundary conditions from the tailing embankment constructed using the downstream and upstream method of rising using OpenSees software. In first case, the model boundary was fixed in both the X and Y directions, and in the second case, viscous dashpots were introduced for both side and horizontal boundaries. The model was validated with experimental results on tailing material. Analyses were carried out considering five different earthquake motions, which were applied at the base. Comparisons of the different boundary conditions in terms of displacement flow vectors, pore pressure and stress-strain curves during shaking are presented. From the analysis, it was observed that the viscous boundary condition replicates the actual field conditions more accurately than the fixed boundary condition. In addition, it was found that the tailing embankment constructed by the downstream and upstream method of rising is not susceptible to liquefaction and lateral spreading for earthquake motions, even for a magnitude > 5.5. [ABSTRACT FROM AUTHOR]