Training Program on Analysis and Design of Dams (Gravity, Embankment, Arch, RCC)

285 Pages·2014·13.26 MB·English

Training Program on
Analysis and Design of Dams
(Gravity, Embankment, Arch, RCC)
For officials of Government of Bihar

01-06 December 2014

Organized by
National Water Academy, Pune, Maharashtra
at
Water and Land Management Institute, Patna, Bihar

Program Co-Ordination

Shri D S Chaskar, Director (Designs), NWA, Pune, &
Shri Sanjay Kumar Srivastava, System Administrator, WALMI, Patna
Table of Contents

1. Overview of Dams 01
by Shri D S Chaskar, Director – Designs, National Water Academy, Pune
2. Site selection, selection of site specific dam type, Layout setting and 18
planning
by Shri A K Nayak, Superintending Engineer (C), ME&RO, Central Water
Commission, Bhubaneswar
3. Design of Concrete Gravity Dams 34
by Shri A K Nayak, Superintending Engineer (C), ME&RO, Central Water
Commission, Bhubaneswar
4. Design of Spillways 48
by Shri A K Nayak, Superintending Engineer (C), ME&RO, Central Water
Commission, Bhubaneswar
5. Design of Energy Dissipaters 67
by Shri A K Nayak, Superintending Engineer (C), ME&RO, Central Water
Commission, Bhubaneswar
6. Planning and Design of Concrete/Masonry Dams 89
(Koteshwar Hydroelectric Project, Uttranchal – a case study)
by Shri A K Nayak, Superintending Engineer (C), ME&RO, Central Water
Commission, Bhubaneswar
7. Planning and Design of Hydro-Mechanical Equipment for Dams 102
by Shri D S Chaskar, Director – Designs, National Water Academy, Pune
8. Design Concepts for Earth & Rockfill Dams 135
by Shri Ramesh Kumar, Superintending Engineer (KCC), KGBO, Central Water
Commission, Hyderabad
9. Design of Core and Filter in Earth and Rockfill Dams 156
by Shri Ramesh Kumar, Superintending Engineer (KCC), KGBO, Central Water
Commission, Hyderabad
10. Importance of Model Studies in Dam Design 169
by Shri Rizwan Ali, Scientist’D’, Central Water &Power Research Station,
Pune
11. Application of Finite Element Method in Static Analysis of Dam 194
by Shri Rizwan Ali, Scientist’D’, Central Water &Power Research Station,
Pune
12. Application of Finite Element Method in Dynamic Analysis of Dam 213
by Shri Rizwan Ali, Scientist’D’, Central Water &Power Research Station,
Pune
13. Foundation Treatment of Dams 233
By Shri S K Sibal, Director-Embankment(NW&S) Dte., Central Water
Commission, New Delhi
14. An Introduction to Roller Compact Concrete Dams 267
By Shri V C Shelke, Chief Engineer (Retd), Govt of Maharashtra
15. An Introduction to Roller Compact Concrete Dams – a case study of 277
Ghatghar Project
By Shri V C Shelke, Chief Engineer (Retd), Govt of Maharashtra
Chapter-1

Overview of Dams
Basic Concept

A Dam is a hydraulic structure of
impervious material built across a
river to create a reservoir on its
upstream side for impounding water
for various purposes.

Types of Dams

• Gravity Dams

• Arch Dams

• Buttress Dams

• Earthen Dams

• Rock fill Dams

• Steel Dams

• Timber Dams

• Rubber Dams

• Arch Dams

A nalysis and Design of Dams – Government of Bihar Page 1
• Arch Dams - Single curvature or
Double curvature

• Buttress Dams

• Earthen Dams

A nalysis and Design of Dams – Government of Bihar Page 2
 Rock fill Dams

• Steel Dams

 Timber Dams

A nalysis and Design of Dams – Government of Bihar Page 3
 Rubber Dams

A nalysis and Design of Dams – Government of Bihar Page 4
Classification based on Purpose of Dam

 Storage dams are constructed to create a
Storage Dam
reservoir to store water during periods

when there is huge flow in the river for
utilization later during periods of low
flow. Water stored in the reservoir can be
used for irrigation, power generation,
water supply etc. It may also be used as
detention dam if regulated accordingly.

 Detention dam is constructed to
Detention Dam
temporarily detain all or part of the flood
water in a river and to gradually release
the stored water later at controlled rates
so that the entire region on the
downstream side of the dam is protected
from possible damage due to floods. It
may also be used as a storage dam.

 It is constructed to divert part of or all
Diversion Dam
the water from a river into a conduit or a

channel. Mostly a diversion weir is
constructed across the river for diverting
water from a river into an irrigation
canal.
A nalysis and Design of Dams – Government of Bihar Page 5
 It is a temporary dam constructed to
Coffer Dam
exclude water from a specific area. It is

constructed on the upstream side of the
site where a dam is to be constructed so
that the site remains dry during
construction.

 It is constructed to catch and retain debris
Debris Dam
flowing in a river.

Storage v/s ROR

Storage Scheme

Storage dams are constructed to create a reservoir to store water during monsoon
periods when there is huge flow in the river

The stored water is then utilized later on during periods of lean flow.

Water stored in the reservoir can be used for irrigation, power generation, water
supply etc.

ROR Scheme

ROR stands for Run-of-River scheme

In ROR scheme, the water is stored during low power demand, which is utilized
during high power demand.

Run-of-River projects are constructed where no storage or a limited amount of
storage is available.

Classification Based on Hydraulic Design

Non Over Flow Dam

The Dam portion which does not allow to escape flood waters are called Non
Over Flow Dams.

Over Flow Dam

This is the dam portion which is used for escaping flood waters is called Over
Flow Dam.

A nalysis and Design of Dams – Government of Bihar Page 6
Overflow / Non-overflow section

Classification Based on Construction Material


Rigid Dam

Made of stone, masonry, concrete, steel, or timber

Non-rigid Dam

Made of earth, rock fill etc.

Composite Dam

Earthen dams are provided with a stone masonry or concrete overflow (spillway)
section

Design Aspects – Gravity Dams

Loads on Dams

Dead loads

Reservoir and Tail water loads

Uplift pressures

Earthquake forces

As per IS :1893 -1984

Inertial forces of dam body and hydrodynamic forces

Silt pressure

Ice pressure (for freezing conditions)

Wave loads

Thermal stresses

A nalysis and Design of Dams – Government of Bihar Page 7
Dead Loads

Self weight

Weight of other structures on dam body

Spillway piers

Gates

Bridge, etc.

Unit weigths


Plain Concrete : 2400 kg/m3


Reinforced Concrete : 2500 kg/m3


Masonry : 2300 kg/m3

Water and Silt Loads

Hydrostatic Water Load


Hydrostatic Triangular Distribution taking unit wt. of water as 1000 kg/m3

Weight of flowing water over spillway neglected

Silt Load


Horizontal silt and water pressure is determined as if silt and water have a
horizontal unit weight of 1360 kg/m3


Vertical silt and water pressure is determined as if silt and water have a vertical
unit weight of 1925 kg/m3

Uplift Loads

Act over 100% of the area

Uplift pressures are not affected by earthquakes

A nalysis and Design of Dams – Government of Bihar Page 8