CAREN TAILINGS DAM

Julio Echevarría S.1, Luis Felipe Aguirre W.2, Luis San Martín M.3

1, Ingeniero Civil Codelco, JEchevar@codelco.cl

2, Ingeniero Civil Codelco, LAgui011@codelco.cl

3,Ingeniero Civil, SMI Ingenieros, smart@smi-chile.cl

• Caren Reservoir is located 90

km south west of Santiago

• It has served since 1986 for the

disposal of tailings generated

by El Teniente

• The dam was designed in 12

stages , with a final height of

about 140 m and capacity of 2

billion m3 (term of the live:

about year 2064)

• The dam is ready built up to

Stage 5

INTRODUCCTION

MAIN FEATURES OF THE STAGE 5

• Tailings Storage Capacity up to Stage 5 :710.000.000 m³

• Tailings Disposal Area :19 km²

• Total volume fillings up to Stage 5 :14.000.000 m³

• Height up to Stage 5 : 84m

• Crest Length :900m

• Upstream Slope (H: V) :2:1

• Downstream Slope (H: V) :2:1

DAM FOUNDATIONS

• The alluvial deposit in the valley

reach depths of up to 115 m.

• The first 10 m correspond to fluvial

low density sands, potentially

liquefiable. This soil was replaced

with compacted materials

• Below that soil, exists gravel with

some clay lenses and clayey sands.

SLOPE STAGE 4

SLOPE STAGE 5

DESCRIPTION OF THE DAM

• Up to Stage 4, dam had a core of fine material located on the

upstream face and in the downstream shell, a coarse material.

Between the two sectors, a drainage chimney system was placed.

2.5

1

31

1a Etapa: 181.4

2a Etapa: 192.7

3a Etapa: 201.6

4a Etapa: 209.8

1A

11

1

1.5 2.5

1

2

1

23

4

5

Dren Chimenea

DESCRIPTION OF THE DAM

• Due to the low availability of materials, near the dam. In the stage

5, downstream shell material was replaced for a quarried rock, and

chimney drain was eliminated.

31

4a Etapa: 209.8

5a Etapa: 219.02

1

21

2.51

4a Etapa: 209.8

5a Etapa: 219.0

1A

2B

21

2

13B

21

3A

• The proposal of the new

design was to change the

downstream shell material.

SPECIFICATIONS OF MAIN MATERIALS

• Materials 1A: Impervious Core Material

– Fines Percentage (#200) : 25-70%

– Maximum Size 3” : only isolated boulders.

– Plasticity Index : 5-25

– Layers of 30cm thickness

– Density compaction of 95% of Modified Proctor

• Materials 3B: Massive Rockfill

– Maximum Size : 85% layer thick

– Size 1” :<50%

– Fine material (#200) : <6%

– Uniformity coefficient : D60/D10>15

– Layers of 80 cm thickness

– Minimum density : 2, 12 T/m3.

– Compaction: 6 passes, 5t/m static weight roller

DESCRIPTION OF THE DAM

• For Stage 5 was chosen a downstream slope of 2:1 (H: V). In the

following stages, the slope will be increased up to 1.6:1 (H: V).

31

4a Etapa: 209.8

12a Etapa: 276.0

2

1

1.61

2.51

1.71

1.75

11.8

1

1.851

1.91

11a Etapa: 270.0

10a Etapa: 262.0

9a Etapa: 254.0

8a Etapa: 246.0

7a Etapa: 237.0

6a Etapa: 228.0

5a Etapa: 219.0

1.951

21

3B

1A

2B3A

FEBRUARY 27 2010 EARTHQUAKE BEHAVIOR

• Earthquake of 8,8 Richter

magnitude (Epicentre was located

400 km from the dam)

• At that time, 25% of stage 5 was

built.

• Only minor cracks (5 to 6 mm)

were detected near the

abutments.

CONCLUSIONS

• Change the materials had a big impact to reduce costs

and schedules.

• The “new” design was immediately tested, due to a big

earthquake. The dam had a good behavior.

• This innovative change is being taking account in future

projects and studies on Codelco.

THANKS

DYNAMIC ANALISYS

• Sismo de Diseño:

– Magnitud: 8.0

– Aceleración máxima horizontal:

0,88g

– Aceleración máxima vertical:

0,57g

• Resultados Etapa 12

– Máximo Horz. : 0,4 m

– Remanente Horz : 0,1 m

– Máximo vertical. : 0,2 m

– Remanente vert. : 0,1 m

– Acel. Max. Horz. : 0,56 g

FLAC (Version 6.00)

LEGEND

25-Nov-08 17:24 step 0 2.800E+03 <x< 3.406E+03 -1.391E+02 <y< 4.666E+02

User-defined GroupsFundacionLama-E1Lama-E2Lama-E3Lama-E4Lama-E5Lama-E6Lama-E7Lama-E8Lama-E9Lama-E10Lama-E11Lama-E12Espaldon-E1Nucleo-E1Nucleo-E2Espaldon-E2Nucleo-E3

-0.500

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1.500

2.500

3.500

4.500

(*10^2)

2.850 2.950 3.050 3.150 3.250 3.350(*10^3)

JOB TITLE : Embalse Carén : Alternativa Crecimiento Nucleo - Enrocado

FLAC (Version 6.00)

LEGEND

25-Nov-08 17:24 step 0 2.800E+03 <x< 3.406E+03 -1.391E+02 <y< 4.666E+02

User-defined GroupsFundacionLama-E1Lama-E2Lama-E3Lama-E4Lama-E5Lama-E6Lama-E7Lama-E8Lama-E9Lama-E10Lama-E11Lama-E12Espaldon-E1Nucleo-E1Nucleo-E2Espaldon-E2Nucleo-E3

-0.500

0.500

1.500

2.500

3.500

4.500

(*10^2)

2.850 2.950 3.050 3.150 3.250 3.350(*10^3)

JOB TITLE : Embalse Carén : Alternativa Crecimiento Nucleo - Enrocado

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