13-02-2013, 09:40 AM
A PRESENTATION ON CLASSIFICATION OF DAMS AND SPILLWAYS
A PRESENTATION .ppt (Size: 2.79 MB / Downloads: 186)
DAM
Dam is the most important and expensive structure in hydro-electric power plant.
A Dam is a barrier to raise the water for storage or diversion to create a hydraulic head.
A Hydro-electric dam diverts the flow from the river to the turbines and usually increases the head.
Site for dam mainly depends on a large number of factors such as geological, availability of material, labour cost and others.
Important Points For Dam
Must be permanently stable
Watertight
Low maintenance cost
Simple in construction
Economical
Needs For Dam Construction
Drinking and domestic water supply
Flood control
Irrigation
Industrial water supply
control of sediments
Hydroelectric energy production
Fish Farming
EARTH FILL DAM
This type is a popular type and more economical for sites where excavation of foundation soil is considerable.
The dam is made by utilizing various earth materials like rock,gravel,sand,flour and clay.
It is cheaper than masonry dam
Not suitable for spillway structure.
ROCK FILL DAM
This type of dam consists of loose rocks of all sizes
It has a trapezoidal shape with wider base with a water tight section to reduce seepage.
It is mainly used mountaneous locations where rocks rather than earth is available.
It requires a supplementary spillways.
High resistance to earthquake
GRAVITY DAM
This type of dam is more massive type and bulky than other type.
This type of dam is built of masonry, mortar or concrete.
The height of this dam is limited by strength of available foundation.
These are simplest in design but they carry massive volume of material.
SPILL WAYS
When the water in the reservoir increases, the large accumulation of water endangers the stability of the dam structure. To avoid this a structure is provided in the body of a dam or near the dam or periphery of the reservoir. This structure is called as spillway.
Mainly used to discharge water during flood period.
Requirements:
Provide structural stability to the dam under all condition
Should able to pass the designed flood without raising the reservoir level above H.F.L.
Should have an efficient operation
Should be economical