How to Prevent Flow Failures in Tailings Dams

[EN] Based on research carried out at 67 tailings dams in Spain: (1) tailings dams contain alternating sedimentary layers with contractive and dilative geomechanical behaviours; (2) tailings saturate quickly but drain more than 10 times slower due to the high-suction capacity of the porous sediments...

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Detalhes bibliográficos
Autores: Rodríguez Pacheco, Roberto Lorenzo, Muñoz Moreno, Alejandro, Caparrós-Ríos, Ana Vanesa, García-García, Cristóbal, Brime Barrios, Ángel, Arranz González, Julio César, Rodríguez Gómez, Virginia, Fernández Naranjo, Francisco Javier, Alcolea-Rubio, Luis Alberto
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2021
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/346722
Acesso em linha:http://hdl.handle.net/10261/346722
https://api.elsevier.com/content/abstract/scopus_id/85101261327
Access Level:Acceso aberto
Palavra-chave:Tailings management facilities
Double drainage system
Liquefaction
Storage-cover release
Descrição
Resumo:[EN] Based on research carried out at 67 tailings dams in Spain: (1) tailings dams contain alternating sedimentary layers with contractive and dilative geomechanical behaviours; (2) tailings saturate quickly but drain more than 10 times slower due to the high-suction capacity of the porous sediments (2–300 MPa); and (3) over the long-term, a stationary flow regime is attained within a tailings basin. Four temporal and spatial conditions must all be present for a tailing dams flow failure to occur: (1) the tailings must experience contractive behaviour; (2) the tailings must be fully saturated; (3) the effective stress due to static or dynamic load must approach zero; and (4) the shear stress must exceed the tailings residual shear stress. Our results also indicate that the degree of saturation (Sr) is the most influential factor controlling dam stability. The pore-pressure coefficient controls geotechnical stability: when it exceeds 0.5 (Sr = 0.7), the safety factor decreases dramatically. Therefore, controlling the degree of tailings saturation is instrumental to preventing dam failures, and can be achieved using a double drainage system, one for the unconsolidated foundation materials and another for the overlying tailings.