SAMARCO – IMMEDIATE
CAUSES TO THE FAILURE
OF THE FUNDÃO DAM
SUMMARY OF CONCLUSIONS PRESENTED BY
THE FUNDÃO TAILINGS DAM REVIEW PANEL
2016-10-12 / SVEMIN MILJÖKONFERENS / GÄLLIVARE
SWECO GRUVDAMMAR OCH DEPONERINGSHANTERING
JONAS JONSSON, MAGNUS LJUNGGREN
1
10/24/2016
SAMARCO – IMMEDIATE
CAUSES TO THE FAILURE
OF THE FUNDÃO DAM
SUMMARY OF CONCLUSIONS PRESENTED BY
THE FUNDÃO TAILINGS DAM REVIEW PANEL
Rio de Janeiro
Sao Paulo
2016-10-12 / SVEMIN MILJÖKONFERENS / GÄLLIVARE
SWECO GRUVDAMMAR OCH DEPONERINGSHANTERING
JONAS JONSSON, MAGNUS LJUNGGREN
2
10/24/2016
Introduction
• In 2015 on November 5 the 110 m high
Fundão Tailings Dam failed in a liquefaction
flowslide.
• More than 60 Mm3 of tailings and water
spread as a mud flow in the river system
along its 650 km path to the Atlantic Ocean.
• In total 18 people lost their lives.
• The owner Samarco Mineração S.A. (BHP
Billiton Brazil Ltda, Vale S.A.) initiated The
Fundão Tailings Dam investigation to
determine its cause
http://www.samarco.com/en/balanco/ (161011)
http://www.argentinaindependent.com/currentaffairs/analy
sis/revisiting-brazils-worst-ever-environmental-disaster/
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
2016-10-24
Introduction
• In 2015 on November 5 the 110 m high
Fundão Tailings Dam failed in a liquefaction
flowslide.
Fundão dam
• More than 60 Mm3 of tailings and water
spread as a mud flow in the river system
along its 650 km path to the Atlantic Ocean.
• In total 18 people lost their lives.
• The owner Samarco Mineração S.A. (BHP
Billiton Brazil Ltda, Vale S.A.) initiated The
Fundão Tailings Dam investigation to
determine its cause
Santarém dam
http://www.samarco.com/en/balanco/ (161011)
http://www.argentinaindependent.com/currentaffairs/analy
sis/revisiting-brazils-worst-ever-environmental-disaster/
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
2016-10-24
Introduction
• In 2015 on November 5 the 110 m high
Fundão Tailings Dam failed in a liquefaction
flowslide.
• More than 60 Mm3 of tailings and water
spread as a turbidity plume in the river
system along its 650 km path to the Atlantic
Ocean.
• In total 18 people lost their lives.
• The owner Samarco Mineração S.A. (BHP
Billiton Brazil Ltda, Vale S.A.) initiated The
Fundão Tailings Dam investigation to
determine its cause
http://www.samarco.com/en/balanco/ (161011)
http://www.argentinaindependent.com/currentaffairs/analy
sis/revisiting-brazils-worst-ever-environmental-disaster/
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
2016-10-24
Introduction
• In 2015 on November 5 the 110 m high
Fundão Tailings Dam failed in a liquefaction
flowslide.
• More than 60 Mm3 of tailings and water
spread as a turbidity plume in the river
system along its 650 km path to the Atlantic
Ocean.
• In total 18 people lost their lives.
• The owner Samarco Mineração S.A. (BHP
Billiton Brazil Ltda, Vale S.A.) initiated The
Fundão Tailings Dam investigation to
determine its cause
http://www.samarco.com/en/balanco/ (161011)
http://www.argentinaindependent.com/currentaffairs/analy
sis/revisiting-brazils-worst-ever-environmental-disaster/
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
2016-10-24
Introduction
• In 2015 on November 5 the 110 m high
Fundão Tailings Dam failed in a liquefaction
flowslide.
• More than 60 Mm3 of tailings and water
spread as a turbidity plume in the river
system along its 650 km path to the Atlantic
Ocean.
• In total 18 people lost their lives.
• The owner Samarco Mineração S.A. (BHP
Billiton Brazil Ltda, Vale S.A.) initiated The
Fundão Tailings Dam investigation to
determine its cause
http://www.samarco.com/en/balanco/ (161011)
http://www.argentinaindependent.com/currentaffairs/analy
sis/revisiting-brazils-worst-ever-environmental-disaster/
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
2016-10-24
70 000 000
Introduction
60 000 000
50 000 000
60 000 000
Overview of release from tailings dam
failures during the last 20 years
50 000 000
Approx. release [m3]
40 000 000
30 000 000
20 000 000
10 000 000
0
-10 000 000
Failures with approximated amount of release
Failures with unknown amount of release
Source: www.Wise-uranium.org / Tailings Dam Incidents,
U.S. Committee on Large Dams - USCOLD, Denver,
Colorado, ISBN 1-884575-03-X, 1994
8
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
2016-10-24
Immediate causes to the Fundão
dam failure
Reference:
Fundao Tailings Dam Review Panel – Report on the
immediate Causes of the Failure of the Fundao Dam,
August 25, 2016
http://fundaoinvestigation.com/
Panel: Norbert R. Morgenstern (Chair), Steven G. Vick,
Cassio B. Viotti, Bryan D. Watts
• Start of construction: 2007
• Dam type: Upstream raised tailings dam
• Dam height at failure: 110 m (EL +900 m)
Level crest at
failure
ADDED TEXT AND SKETCHES ON THE REVIEW PANEL’S REPORT
FIGURES ARE FOR EXPLANATORY PURPOSES ONLY DURING THE
PRESENTATION.
Beach of
sand tailings
Compacted
berms of tailings
Starter
dam
Underdrain
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
Original figure from Panel report:
http://fundaoinvestigation.com/
9
2016-10-24
Immediate causes to the Fundão
dam failure
Reference:
Fundao Tailings Dam Review Panel – Report on the
immediate Causes of the Failure of the Fundao Dam,
August 25, 2016
http://fundaoinvestigation.com/
Panel: Norbert R. Morgenstern (Chair), Steven G. Vick,
Cassio B. Viotti, Bryan D. Watts
• Start of construction: 2007
• Dam type: Upstream raised tailings dam
• Dam height at failure: 110 m (EL +900 m)
Level crest at
failure
ADDED TEXT AND SKETCHES ON THE REVIEW PANEL’S REPORT
FIGURES ARE FOR EXPLANATORY PURPOSES ONLY DURING THE
PRESENTATION.
Beach of
sand tailings
Compacted
berms of tailings
Starter
dam
Underdrain
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
Original figure from Panel report:
http://fundaoinvestigation.com/
10
2016-10-24
Immediate causes to the Fundão
dam failure
Reference:
Fundao Tailings Dam Review Panel – Report on the
immediate Causes of the Failure of the Fundao Dam,
August 25, 2016
http://fundaoinvestigation.com/
Panel: Norbert R. Morgenstern (Chair), Steven G. Vick,
Cassio B. Viotti, Bryan D. Watts
• Start of construction: 2007
• Dam type: Upstream raised tailings dam
• Dam height at failure: 110 m (EL +900 m)
Level crest at
failure
ADDED TEXT AND SKETCHES ON THE REVIEW PANEL’S REPORT
FIGURES ARE FOR EXPLANATORY PURPOSES ONLY DURING THE
PRESENTATION.
Beach of
sand tailings
Compacted
berms of tailings
Starter
dam
Underdrain
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
Original figure from Panel report:
http://fundaoinvestigation.com/
11
2016-10-24
Immediate causes to the Fundão
dam failure
Reference:
Fundao Tailings Dam Review Panel – Report on the
immediate Causes of the Failure of the Fundao Dam,
August 25, 2016
http://fundaoinvestigation.com/
Panel: Norbert R. Morgenstern (Chair), Steven G. Vick,
Cassio B. Viotti, Bryan D. Watts
• Start of construction: 2007
• Dam type: Upstream raised tailings dam
• Dam height at failure: 110 m (EL +900 m)
Level crest at
failure
ADDED TEXT AND SKETCHES ON THE REVIEW PANEL’S REPORT
FIGURES ARE FOR EXPLANATORY PURPOSES ONLY DURING THE
PRESENTATION.
Beach of
sand tailings
Compacted
berms of tailings
Starter
dam
Underdrain
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
Original figure from Panel report:
http://fundaoinvestigation.com/
12
2016-10-24
Immediate causes to the Fundão
dam failure
Reference:
Fundao Tailings Dam Review Panel – Report on the
immediate Causes of the Failure of the Fundao Dam,
August 25, 2016
http://fundaoinvestigation.com/
Panel: Norbert R. Morgenstern (Chair), Steven G. Vick,
Cassio B. Viotti, Bryan D. Watts
• Start of construction: 2007
• Dam type: Upstream raised tailings dam
• Dam height at failure: 110 m (EL +900 m)
Level crest at
failure
ADDED TEXT AND SKETCHES ON THE REVIEW PANEL’S REPORT
FIGURES ARE FOR EXPLANATORY PURPOSES ONLY DURING THE
PRESENTATION.
Beach of
sand tailings
Compacted
berms of tailings
Starter
dam
Underdrain
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
Original figure from Panel report:
http://fundaoinvestigation.com/
13
2016-10-24
Liquefaction
• Conditions required:
o Contractive material > volume decreases during
shearing because the particles move together.
o Saturation > all voids are filled with water. If
shearing occurs in a saturated contractive tailings
excessive pore pressure may generate.
o Trigger mechanism, rate of loading vs.
drainage capacity > if the loading (shearing) is
large enough or repeated many times the pore
pressure in the voids may increase to such extent
that friction between the grains is lost.
Sand
grains
Normal pore water
pressure
Saturated soft sand.
Strength maintained
because friction from
the grains touching.
High pore water
pressure
Saturated soft sand.
High pore water pressure
may break the friction
between the grains
causing liquefaction.
14
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
2016-10-24
Series of events and conditions
• The dam failure occurred because of a series of
events and conditions that allowed the failure to take
place
Main incidents and conditions:
a) Year 2009 - Damage to starter dam
b) Year 2011,12 - Slime deposition issues
c) Year 2012 - Shift of the dam crest alignment (the “set
back”)
15
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
10/24/2016
Year 2009: Damage to the Start dam (Dike 1)
• April 2009, large seepage flows
carrying tailings on the downstream
slope.
DAMAGE TO SLOPE
• Seepage flows emerged above
underdrain outlet level.
LEAKAGE WATER
Figure from Panel report:
http://fundaoinvestigation.com/
16
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
2016-10-24
Consequences
• Underdrains were sealed as they could not be repaired.  One of the most
important element became inoperative
• A new blanket drain constructed on the surface of the tailings  The sand
tailings below and upstream of the new blanket drain remained saturated
NEW DRAIN
ONLY SKETCHED
Original figures from Panel report:
http://fundaoinvestigation.com/
UNDERDRAIN
ONLY SKETCHED
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
17
2016-10-24
Year 2011/12 – Slime deposition issues
• During 2011 and 2012 slime was
rerouted through an overflow channel
into the Fundao reservoir.
• The original and revised design
specified a minimum 200 m wide beach
of sand tailings to control saturation.
SAND TAILINGS
SLIMES
Original figures from Panel report: http://fundaoinvestigation.com/
Figure from Panel report: http://fundaoinvestigation.com/
18
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
2016-10-24
Consequences
• Deposition of slimes in areas where this was not intended in design
At times beach only 60 m wide.
Slimes near the downstream slope and below the raised dam construction.
BEACH 200 m WIDE
S L I M E S
Original figures from Panel report: http://fundaoinvestigation.com/
19
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
2016-10-24
Year 2012: The left abutment “Set back”
• In October 2012 the dam alignment (crest)
was moved upstream from its original
design, called the “setback crest”.
• The change due to structural integrity
issues of a abutment concrete gallery, that
drained left abutment run-off water.
SETBACK CREST
Original figures from Panel report: http://fundaoinvestigation.com/
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
20
10/24/2016
Consequences
• The setback had significant effects. Moving the embankment
back, toward the impoundment, caused it to be raised over the
slimes deposited in 2011 and 2012.
SETBACK CREST
S L I M E S
Original figure from Panel report: http://fundaoinvestigation.com/
21
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
2016-10-24
Immediate causes to the Fundão dam failure
• Liquefaction:
Contractive (loose) material
Saturation
Trigger mechanism – liquefaction by
lateral extrusion [Movie clip 2.5 min,
start at 2:53]
IMMEDIATE CAUSES TO THE FAILURE OF THE FUNDÃO DAM / SVEMIN MILJÖKONFERENS 16-10-12 / JONAS JONSSON, MAGNUS LJUNGGREN
22
2016-10-24
Thanks for your attention!!
Magnus Ljunggren
Dam design, inspections, control
+46 72-501 17 21
Jonas Jonsson
+46 76-109 30 84
Tailings management, dam safety, site selection