TC221 Tailing and Mine Wastes

Tailing and Mine Wastes

Stability of tailings dams will be discussed in a webinar on January 20th, 2022.

The International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE) Technical Committee TC221 on Tailings and Mine Wastes is organizing a Tailings and Mine Waste Webinar taking place on 20th January 2022. This webinar was motivated by answers given to a brief questionnaire on some main geotechnical issues associated with the stability of tailing dams. A significant number of responses showed serious divergences on key aspects related to design, analysis and monitoring of tailings dams, prompting the organization of a discussion session.


The 2 hours webinar will be broadcast by the Brazilian Society Channel starting at 14:00 UTC (Coordinated Universal Time)[1], which is considered an appropriate time to facilitate participation in the different time zones.

Broadcast at:


Colleagues with a high expertise on tailings dams and related issues will present the views on the design of tailings dams and how it has evolved with time to ensure better performance, considering the views of the geotechnical community expressed in the answers to TC221 questionnaire.

The debate will begin with presentations by Prof. Jonathan Bray and Prof. Antonio Gens. Then, Ramon Verdugo and Antonio Carraro will address the controversial topic related to the design and maintenance of upstream tailings dams, covering the various geotechnical analyses required throughout the lifecycle of the structure in order to ensure long term stability.

Assessment of the residual (post-liquefaction) undrained shear strength will be addressed by Prof. Fernando Schnaid in support to current engineering practice, whereas Arcesio Lizcano will support a more solid theoretical basis in design.

A third question is referred to monitoring upstream dams with potentially liquefiable tailings zones, identifying the most appropriate instrumentation to prevent flow failure.  Prof. David Williams and Prof. Roberto Cudmani will approach this topic.  

Luis Valenzuela will approach the stability of tailings dams using limit equilibrium analysis. In closing, Mike Jefferies will highlight the need for more robust stress-strain analysis with appropriate constitutive models in supporting engineering design.

The audience will be allowed to make questions to the different topics, which will be discussed during the debate.



The number of tailings dam failures that have occurred systematically over time has left the mining industry in a poor position worldwide. In this context, the ICMM (International Council on Mining & Metals), UNEP (United Nations Environment Programme) and PRI (Principles for Responsible Investment) developed the Global Industry Standard on Tailings Management, which strives to achieve the goal of zero harm to people and the environment with zero tolerance for human fatality. This standard makes clear that extreme consequences to people and the environment from catastrophic tailings facility failures are unacceptable. Consequently, we are experiencing international concerns associated with the stability of tailings dams and a demand to build these deposits safely throughout their project lifecycle. In this new world scenario, the geotechnical engineering associated with the stability analyses of tailings dams acquires a preponderant role. In this context, in July 2021, a short questionnaire of 6 questions (see below) was prepared and sent to the TC221 members. Close to 50 responses were received, which will be discussed in the online event of January 20th.

1.- Is it possible to design upstream tailings dams where their stability can be guaranteed on a long-term basis? If so, which are the basic requirements that an upstream tailings dam must meet?

2.- Which are the most appropriate procedures to evaluate the residual undrained strength (shear strength of liquefied soils) in the laboratory and in the field?

3.- In an upstream dam with zones of potentially liquefiable tailings, what would be the most appropriate instrumentation to monitor the dam for preventing flow failure?

4.- Is it correct to evaluate the stability of tailings dams using limit equilibrium analysis? If so, what would be the acceptable factor of safety for static and pseudo-static conditions?

5.- Would you consider stress-strain analysis with appropriate constitute models a necessary requirement for design?

6.- Do you think it would be useful to write a technical document that addresses the stability of tailings dams built upstream, or on materials that may potentially lose strength?


[1] Sydney 24:00 (UTC+10), Pacific Coast (US/Canada) 6:00 (UTC-8). The time in other time zones can be checked under

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Disseminate and develop knowledge and practice within the TCs subject area to the membership of the ISSMGE.

To promote cooperation and expertise exchange in tailings and mine wastes, the following activities are proposed:

1.- Create a website for this TC about tailings and mine wastes.

2.- Host a special session on tailings and mine wastes at the next ICSMGE, Sydney 2021.

3.- Organize the First Int. Conf. on Tailings and Mine Wastes during 2023. The following topics are considered:

- Methods of Tailings Disposal and Resulting Properties in Tailings Deposits

- Design of Tailings Dams for Static and Seismic Conditions

- Seepage from Tailings Storages and Through Tailing Dams

- Impact of Tailings Dams Failures

- Design of Leaching Pads

- Static and Seismic Stability of Waste Rock Dumps

4.- Due to the pandemic, the Conference has been replaced by an online debate on hot topic regarding the stability of tailings dams.


Establish guidelines and technical recommendations within the TCs subject area. To fulfill this objective, the new TC on Tailings and Mine Waste will focus on the following actions:

1.- Identify the codes or provisions currently available in important mining countries (translating to English if needed) and present them in the TC website.

2.- Analyze the available reports of the dam failures of Mount Polley and Samarco and present them, together with the results of the analysis, in the TC website

3.- Identify state of the art lectures, state of the practice lectures and keynote lectures that have been delivered in the last 20 years and present them in the TC website.

4.- Identify critical aspects of tailings deposits and mine waste management, as governance and dam safety.

Assist with technical programs of international and regional conferences organized by the ISSMGE. The TC221 on Tailings and Mine Waste will focus on the following actions:

1.- Host a special session on tailings and mine wastes at the next ICSMGE, Sydney 2022.

2.- Promote the presence of special sessions on tailings and mine wastes at regional conferences.

3.- Encourage the active participation (papers, lectures, workshops) of the TC members at different Conferences.

Interact with industry and overlapping groups working in areas related to the TCs specialist area. The TC221 on Tailings and Mine Waste will do the following actions:

1.- Considering that the competencies of ISSMGE and ICOLD are complementary in the area of tailings dams, the interaction and contact between ISSMGE and ICOLD in this topic is beneficial for both groups, and it should be promoted. Accordingly, it is proposed the development of an active interaction with ICOLD. This interaction will start with the ICOLD-Chile, taking advantage of the fact that several geotechnical engineers are members of both institutions. Specifically, a Technical Bulletins on seismic aspects of tailings dam design will be proposed.

2.- Involve in the TC at least four important Mine Companies that collaborate for an effective interaction between the private sector and the academia.

3.- Reduce the gap between the State-of-the-Art and the State-of-the-Practice through an effective interaction between practitioners and academic researchers via specific workshops that will be held in different mining countries.

4.- Interact with national and international standards committees and call for workshops on relevant topics.


# Type Full Name Country
1 Chair Ramón Verdugo Chile
2 Vice Chair Roberto Cudmani Germany
3 Secretary Fernando Schnaid Brazil
4 Nominated by TC Chair Norbert Morgenstern Canada
5 Nominated by TC Chair Michele Jamiolkowski Italy
6 Nominated by TC Chair Luis Valenzuela Chile
7 Nominated by TC Chair Susumu Yasuda Japan
10 Corresponding Member Lin WANG Japan
11 Nominated Member Mayu Tincopa Peru
12 Corresponding Member Young-Suk SONG South Korea
13 Nominated Member Christopher Beckett United Kingdom
14 Nominated Member Antonio Carraro United Kingdom
15 Corresponding Member Elisabeth Bowman United Kingdom
16 Corresponding Member Stephen Thomas United Kingdom
17 Corresponding Member Daniel Barreto United Kingdom
18 Corresponding Member Lidija Zdravkovic United Kingdom
19 Corresponding Member Truong Le United Kingdom
20 Corresponding Member Peter Jones United Kingdom
21 Corresponding Member Matteo Ciantia United Kingdom
22 Nominated Member Shi-Jin Feng China
23 Nominated Member Yongfeng DENG China
24 Corresponding Member Jiang-shan Li China
25 Corresponding Member Dudley Brown United Kingdom
26 Nominated Member Shaw Shong Liew Malaysia
27 Nominated Member Luiz Guilherme De Mello Brazil
28 Nominated Member MÁRCIO ALMEIDA Brazil
29 Nominated Member Steven Kramer United States
30 Nominated Member Alejandro Martinez United States
31 Corresponding Member José Antonio Fernández Spain
32 Nominated Member Paolo Simonini Italy
33 Corresponding Member Nicola Brusa Italy
34 Corresponding Member Daniele Cazzuffi Italy
35 Corresponding Member Paolo Croce Italy
36 Corresponding Member Johann Facciorusso Italy
37 Corresponding Member Lucia Simeoni Italy
38 Corresponding Member Andy Fourie Australia
39 Nominated Member B. Hanumantha Rao India
40 Corresponding Member H.N. Ramesh India
41 Nominated Member Koldobika Sánchez Arrotegui Spain
42 Nominated Member Marcos Arroyo Spain
43 Corresponding Member Diego Manzanal Spain
44 Nominated Member Jean-François Vanden Berghe Belgium
45 Nominated Member Waldemar Świdziński Poland
46 Nominated Member Andrzej Gruchot Poland
47 Corresponding Member Dang Minh Su Vietnam
48 Nominated Member Richard Jewell Belgium
49 Nominated Member Laura Carbone Germany
50 Nominated Member Joan Manuel Larrahondo Colombia
51 Nominated Member Brahian Roman Peru
52 Nominated Member Jan Laue Sweden
53 Nominated Member Sven Knutsson Sweden
54 Nominated Member Jun Yang Hong Kong Special Administrative Region
55 Nominated Member Jesse Tam Hong Kong Special Administrative Region
56 Corresponding Member John Cowland Hong Kong Special Administrative Region
57 Corresponding Member Jeff Wang Hong Kong Special Administrative Region
58 Nominated Member Ioannis Zevgolis Greece
59 Nominated Member Alejo Sfriso Argentina
60 Nominated Member LUCIANO OLDECOP Argentina
61 Corresponding Member Rafael Monroy United Kingdom
62 Nominated Member Nuno Cristelo Portugal
63 Nominated Member Eoin McGrath Ireland
64 Corresponding Member Mohammad Rezania United Kingdom
65 Nominated Member Nikolay Milev Bulgaria
66 Nominated Member Hongjie Zhou Australia
67 Corresponding Member David Solans United Kingdom
68 Corresponding Member Mark Bruton United Kingdom
69 Nominated Member Adrian Russell Australia
70 Nominated Member Sarat Das India
71 Corresponding Member Harold Mantilla Peru
72 Nominated Member Øyvind Torgersrud Norway
73 Nominated Member Luca Piciullo Norway
74 Corresponding Member edgard bard Chile
75 Corresponding Member sergio barrera Chile
76 Corresponding Member jose campaña Chile
77 Corresponding Member alvaro huerta Chile
78 Corresponding Member emilio lopez Chile
79 Corresponding Member eloy santos Chile
80 Corresponding Member rene orellana Chile
81 Corresponding Member carolina palma Chile
82 Corresponding Member Cesar Pasten Chile
83 Corresponding Member Carolina Vergara Chile
84 Corresponding Member Raúl Espinace Chile
85 Nominated Member Gonzalo Suazo Chile
86 Corresponding Member Camilo Morales Chile
87 Nominated Member Marcelo Gonzalez Chile
88 Nominated Member Antonio Viana da Fonseca Portugal
89 Nominated Member Mamadou Fall Canada
90 Corresponding Member Srinivasan V India
91 Nominated Member Mitsu Okamura Japan
92 Corresponding Member Takemine Yamada Japan
93 Corresponding Member Susumu Yasuda Japan
94 Nominated Member Takashi Kiyota Japan
95 Nominated Member Andrés Peña Germany

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