In recent years, the use of filtered dry stacked tailings has steadily increase in the mining industry as it is an innovative solution for the construction of tailings storage facilities (TSF). This technology allows increasing the safety of tailings dams, enhance the recovery of water for mining processes and enables the construction of co-disposal techniques. However, many of these facilities are located in zones prone to megathrust earthquake events. Hence, the dynamic behavior of filtered tailings facilities must be assessed to ensure its satisfactory seismic performance.
To evaluate this, two advanced plasticity-based constitutive models (SANISAND-Sf and PM4Sand) were implemented in a finite difference software and applied in a real project located in zones where peak ground accelerations of 0.7g and higher are expected. Geotechnical characterization was carried out from advanced laboratory testing which allowed a proper calibration of the tailings and the foundation materials.
The simulation results showed that both constitutive models produced similar overall response of the facility and similar shear strain patterns with progressive slope instability as the main mechanism. However, the SANISAND-Sf model showed slightly higher vertical and horizontal deformations than PM4sand at full scale modelling, whereas PM4sand showed more deformations at single-element modelling. Moreover, a sensitivity analysis was performed to examine the effect of different ground motions spectrally matched to the Peak Ground Acceleration corresponding to the Maximum Credible Earthquake of the area (0.70g) noticing that the Maule earthquake (Chile, 2010) generates the higher displacements and strains.
Finally, implications of the dynamic analysis on design decision-making and some suggestions for the path towards a performance-based design standard of practice are provided.
Authors
Brahian Roman, SRK Consulting Peru
Martín Villanueva, SRK Consulting Peru
Andrés Barrero, SRK Consulting Canada
Arcesio Lizcano, SRK Consulting Canada
Presenter:
Brahian Roman, SRK Consulting Peru
