Behaviour of Dams and Briges

8/13/2019 Behaviour of Dams and Briges

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BEHAVIOUR OF DAMS AND

BRIDGES IN PASTEARTHQUAKE

By,

Poorani Saravana Priya.P


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REASONS THAT LEAD TO

FAILURE Structural failure of materials used in dam

construction.

Movement and/or failure of the foundationsupporting the dam.

Settlement and cracking of concrete or

embankment dams.

Piping and internal erosion of soil in

embankment dams.

Inadequate maintenance and upkeep.


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DAMAGES CAUSED

Rock-fill dams are more flexible

than those of concrete and more

resistant than earth dams.

However, the clay or concrete

used to make these dams water-

tight can crack in an earthquake,resulting in leaks.


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Possible damage would include:

Small, medium, or large cracks or

leaks;

Collapse of reservoir embankments;


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Other damages include:

Small leaks which should be

immediately repaired to avoid the

increase of erosion;

Accumulation of soil because of

landslides, which may need to be

dredged;


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CONCRETE DAMS Concrete dams can crack or the

foundations can fail.

Possible damage could include:

Cracks or small leaks that should be

repaired immediately;

Accumulation of soil due to slides;


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Broken spillways of ShihKang dam


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SEISMIC LIQUEFACTION


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SEISMIC LIQUEFACTION

Seismic liquefaction refers to a sudden

loss in stiffness and strength of soil

due to cyclic loading effects of anearthquake.


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SAN FERNANDO DAM


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KOYNA DAM-INDIA

The most important

structural damage to

the dam was horizontal

cracks on the upstream

and downstream faces


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Fujinuma Dam Failure

March 11, 2011 Japan


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UPSTREAM BREACH


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ABUTMENT SLIDE


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UPSTREAM SLIDE


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ABUTMENT BREACHING


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MAJOR FAILURES

Potential breach resulting from a slope

failure

The failure of the dam reportedly

occurred soon after the earthquake,consistent with a slope stability failure

leading to a breach of the dam.


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SLOPE DISTRESS


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Potential breach resulting from an

internal erosion, or piping failure

If the dam deformed significantly

during the earthquake shaking,transverse cracks could have

developed and promoted internal

erosion.


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EROSION


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SHIH KANG DAM


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BEHAVIOUR OF BRIDGES IN

PAST EARTHQUAKE


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MAJOR DAMAGES

Seismic Displacements

Column Failure

Joint Failure

Footing Failure

Steel Bridge Components


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LIQUEFACTION


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Showa Bridge 1964-Niigata


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Showa Bridge 1964 Niigata

The failure of Showa Bridge is mainly

due to LIQUEFACTION.

The pipe pile sinks directly into the

upper loose sand layer which causes

the 307 m long bridge to sink partially.

CRUSHING FAILURE


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CRUSHING FAILURE


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The crushing failure is mainly due totwo main reasons,

Improper design mix strength

and

Improper reinforcement

This failure occurred in Hyogoken-

Nanbu earthquake


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DETACHMENT OF PILE CAP


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The detachment of pile cap from pilehead is mainly due to,

Improper mixing

Improper Compaction

This failure occurred in Hyogoken-

Nanbu earthquake

PIERS PENETRATE


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PIERS PENETRATE


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Pier penetrating bridge deck due topile settlement or lateral bending

deformation under earthquake

loading. This failure occurred in Struve Slough

bridge, 1989


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LOMA PRIETA EARTHQUAKE


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Example Bullet Point Slide


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Structure lacked redundancy

Structure lacked ductility

Lack of capacity to absorb energy

Longitudinal restrainers helped, but

did not address column ductility.


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NORTHRIDGE


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Failures can be attributed to brittle

shear failure of short stiff columns.

Short stiff column next to abutmentfails

Unseating of hinge

Span collapse


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Documents

Behaviour of Dams and Briges