designof hydraulic structures

1. Presented By
ASHITHA M
DEPARTMENT OF CIVIL ENGINEERING
SPILLWAYS
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2. Spillway
 Structures constructed at a dam site for disposing of the
water from u/s to d/s.
 Safety valve for a dam
Location of Spillway
 within the body of the dam
 At one end of it
 Entirely away from it
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3. TYPES OF SPILLWAYS
 Straight drop spillway (Overfall Spillway)
 Overflow Spillway (Ogee Spillway)
 Chute Spillway (Trough Spillway/Open Channel Spillway)
 Side Channel Spillway
 Shaft Spillway
 Syphon Spillway
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13. Shaft Spillway
 Discharges excess water through a shaft that is
constructed near the crest of the Dam with height
less than that of the crest.
 Used when the other types of spillways cannot be
constructed due to a lack of space.
 not suitable for large capacity and deep reservoirs
because of stability problems.
 Repair and maintenance difficult
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15. Syphon Spillway
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17.  Siphon pipe is installed within the body of the dam
 Valley is narrow and no sepatrate space is available
 Air vent is connected with the syphon pipe
 Level of air vent is normal pol level
 Level of syphon pipe is lower to prevent entry of debris
 When theWL<NPL air enters syphon through air vent pipe
 WhenWL>NPLwater starts flowing through syphon
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18. GALLERY
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