What are the forces acting on dam?

The forces that act on the dam are the following:

Weight of the dam.
Horizontal hydrostatic pressure due to water.
Uplift pressure due to water percolated under the dam.
Earthquake pressure.
Wind pressure.
Ice pressure.
Wave pressure.
Pressure due to silt deposited on U/S face.

Considering this, what are the forces acting on gravity dam?

Gravity Dam Case-I Reservoir Full Case • When reservoir is full, the major forces acting are weight of the dam, external water pressure, uplift pressure, and earthquake forces in serious seismic zones. The minor forces are: Silt Pressure, Ice Pressure, and wave Pressure.

Additionally, how much pressure does a dam hold? A concrete arch-gravity type, in which the water load is carried by both gravity action and horizontal arch action. What is the maximum water pressure at the base of the dam? 45,000 pounds per square foot.

Also asked, what are the various forces acting on arch dams?

Forces Acting on Arch Dams. Generally, the same forces act on arch dam, which do act on a gravity dam. These forces are: (i) water pressure; (ii) Uplift pressure; (iii) earthquake forces; (iv) silt pressure; (v) wave pressure (vi) ice pressure; as discussed in article.

How does a gravity dam work?

A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by primarily using the weight of the material alone to resist the horizontal pressure of water pushing against it.

What is a dam spillway?

A spillway is a structure used to provide the controlled release of flows from a dam or levee into a downstream area, typically the riverbed of the dammed river itself. Floodgates and fuse plugs may be designed into spillways to regulate water flow and reservoir level.

What are the different types of dams?

21 Types of Dams in Construction

Masonry Dam. Masonry dams are built using either stone masonry or brick masonry.
Concrete Dam. Concrete is most commonly used material to construct a dam.
Timber Dam.
Steel Dam.
Earthen Dam.
Rock Fill Dam.
Gravity Dam.
Arch Dam.

Why are dam walls curved?

An arch dam is a concrete dam that is curved upstream in plan. The arch dam is designed so that the force of the water against it, known as hydrostatic pressure, presses against the arch, causing the arch to straighten slightly and strengthening the structure as it pushes into its foundation or abutments.

What is spillway in dams?

A spillway is a structure used to provide the controlled release of flows from a dam or levee into a downstream area, typically the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure that the water does not overflow and damage or destroy the dam.

What is the difference between gravity dam and earthen dam?

An earthen dam is made of earth (or soil). It resists the forces exerted upon it mainly due to shear strength of soil. The gravity dams are massive constructions, built out of concrete or masonry, which counteract the force of water pressure with only action of self mass.

What is gravity dam what are the forces causing stability?

Technically a concrete gravity dam derives its stability from the force of gravity of the materials in the section and hence the name. The gravity dam has sufficient weight so as to withstand the forces and the overturning moment caused by the water impounded in the reservoir behind it.

How can the uplift pressure of a dam be reduced?

Uplift is generally reduced by constructing drainage pipes between dam and its foundation, constructing cut off walls under the upstream face, holes in the dam section, or pressure grouting the dame foundation.

What is spillway and its types?

The types are: 1. Free Over-Fall (Straight Drop) Spillway 2. Ogee (Overflow) Spillway 3. Side Channel Spillway 4. Chute (Open Channel or Trough) Spillway 5.

How do you calculate dams?

The surface area of a dam is calculated by multiplying the length by the width. Example: 30 metres X 50 metres = 1500 m². This will be the case for square or rectangular dams. Most dams start out as a square or rectangle, but over time appear to become rounded.

What is the most economical spacing of buttress?

Irrigation Engineering Questions and Answers – Buttress Dam – Types

S.No	Mean Dam Height in m	Economic buttress spacing
1.	Less than 15	4.5
2.	15 – 30	4.5 to 7.5
3.	30 – 45	7.5 to 12
4.	Above 45	12 to 15

What are the advantages of buttress dams?

Buttress Dams Advantages • Thin section with one-third to one-half economy in concrete compared to gravity dam of similar height • No problem of uplift or foundation drainage • Can be constructed on weak foundations, • Vertical component of water resting against upstream sloping deck add to the stability of the dam.

What is elementary profile of gravity dam?

The elementary profile of a gravity dam is a triangular section having zero width at the water level where hydrostatic pressure is zero, and maximum base width B where maximum hydrostatic pressure head acts.

What is uplift pressure?

An uplift pressure is any upward pressure applied to a structure that has the potential to raise it relative to its surroundings. Uplift forces can be a consequence of pressure from the ground below, surface water and so on.

What is a concrete buttress?

A buttress dam or hollow dam is a dam with a solid, water-tight upstream side that is supported at intervals on the downstream side by a series of buttresses or supports. Most buttress dams are made of reinforced concrete and are heavy, pushing the dam into the ground.

What are the cases for which design of gravity dam is to be checked?

The design of a gravity dam should be checked for two cases, i.e., 1) Reservoir Full Case, and 2) Reservoir Empty Case. When the reservoir is full, the major forces acting are: weight of the dam, external water pressure, uplift pressure, and earthquake forces in serious seismic zones.

What is the unit weight of water?

In the metric, or SI, system the unit weight of water is 998 kg per cubic meter -- kg/m3 -- or approximately 1 g per cubic centimeter, g/cm3. In imperial measurements, the unit weight of water is commonly given as 62.4 pounds per cubic foot, lbs/ft3.

How do you find the depth of a center of pressure?

In other words, the distance from the pivot to the centre of pressure is the depth to the bottom of the vertical plane, minus one third the depth of the submerged part of the vertical plane. So the centre of pressure on a partially submerged plane will always be one third of d up from the base of the plane surface.

How do you calculate the force of water?

Use the formula F=ALC/T to calculate the force of the moving water. F=force, A=average area, L= stream length (20 feet), C=coefficient for the bottom of the water bed, and T=time traveled.

What is a dam wall?

A dam is a barrier that stops or restricts the flow of water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability.