Numerical assessment of drilling-induced static liquefaction triggering of Feijão Dam I

1. Home
2. Publications
3. Online Library
4. Numerical assessment of drilling-induced static liquefaction triggering of Feijão Dam I

Dam I at Vales Córrego do Feijão Iron Ore Mine dam failed on 25 January 2019, resulting in over 250 fatalities and catastrophic economic and environmental damage. Two major investigations have thus far been carried out to investigate the likely triggering event for the failure, leading to different conclusions: (a) a combination of reduction in near-surface suction and drained creep, or (b) liquefaction induced by drilling works occurring at the time of the failure. Other research works published subsequently have suggested either trigger is plausible. The current work reanalysed the liquefaction triggering process to assess whether drilling works, at two sections, could trigger liquefaction first in the immediate area around the borehole by leading to an increase in pore water pressure around the drill hole and then whether this would be sufficient to lead to flow liquefaction of the entire structure. This paper outlines preliminary two dimensional liquefaction triggering analyses of the tailings storage facility (TSF), with the sections representing the location of borehole drilling at the time of the failure and the immediately preceding location. The analyses indicated that the triggering of flow liquefaction was more likely at the location of borehole drilling concurrent with the dam failure, and less likely with the previous borehole drilling. These results are consistent with the observed failure.

10th European Conference on Numerical Methods in Geotechnical Engineering (NUMGE2023)

7. Dams, embankments and slopes