This document discusses different types of dams including earth fill dams, rock fill dams, and concrete dams. It describes how dams are classified based on their construction materials. Earth fill dams can be homogeneous, zoned, or diaphragm. Rock fill dams are constructed by dumping rock in layers. The stability, seepage, drainage, and monitoring of dams are also covered. Reservoir design studies consider the type of reservoir and parameters like stream flow, floods, and water quality.

1. VIDHYADEEP INSTITUTE OF
ENGINEERING AND
TECHNOLOGY
CIVIL ENGINEERING

2. EMBANKMENT
DAM

3. INTRODUCTION
 A dam is an obstruction placed across a river or stream to
perform certain function

4. TYPES OF DAMS
 Storage dam
 Diversion dam
 Detention dam
 Multipurpose dam

5. CLASSIFICATION OF DAMS
 Based on constructional materials we have
 Earth fill dam – made up of locally material
 Rock fill dam – composed of rocks of all sizes to provide
stability and impervious membrane for water seal.
 Concrete gravity dam
 Concrete arch dam

6. EARTH AND ROCK FILL DAMS
• Further classifications
• Homogeneous – Constructed of only one materials
usually of sufficiently impervious materials
• Zoned – Composed of a central impervious core flanked
by zones of considerably pervious materials called
shells.
• Diaphram – Involves the use of a pervious materials to
form a water barrier.

7. PRINCIPLES OF ANALYSIS AND
DESIGN FOR EARTH AND ROCK
FILL DAMS
• Site investigation
• Reconnaissance study – To identify the needed data.
• Site appraisal – Functional suitability of a site must be
governed by the balance between its natural physical
characteristics and the purpose of the reservoir
catchment hydrology
• Study of certain parameters of the environment so that
their normal behaviour can be built into the dam. E.g

8. • Stream flow records
• Flood records
• Wind records
• Ground water data
• Evaporation rates
• Rainfall and temperature records
• Water quality records, etc.

9. DAM SITE EVALUATION
 The nature of the soil and rock formations present,
critical to formations integrity is to be proved by
subsurface exploration.
 Based on all these information, analysis and design
would follow

10. FEASIBILITY REPORT
It is prepared at the conclusion of the
reconnaissance survey and interprets all available
information and data.

11. MATERIALS FOR
CONSTRUCTION
 Earth fill dam – Locally materials
 Rock fill dam – Rocks of all sizes are used for stability
and impervious membrane for water seal.

12. METHODS OF CONSTRUCTIONS
 Rock fill Dam
 Rock placed in layers – Materials are dumped on the
embankment surface and pushed over the advancing
construction face with a bulldozer

13. • Dumped in high sluiced lift – The material is dumped
down the sloping face of the construction lift and sluiced
with high pressure water jets from monitors. The fines
and smaller rocks are deposited at the top of the lift and
the larger rocks slide and rolled down the face of the
slope to the lower part of the lift.
• Earth fill Dam
• Excavate the materials
• Hauling to the dam,
• Mixed to predetermine water content and uniformity of
properties
• Spread it in layers and
• Compact to desire density

14. ADVANTAGES OF
CONSTRUCTION IN LAYERS
• Rock with a higher percentage of fines can be placed,
there is less danger segregation of fines accumulations
• Embankment obtained is more denser, uniform and less
compressible
• It can be built with any slide slope inclination but rock
fill dumped in high lift is placed on the angle of repose
of the materials
• etc

15. STABILITY
 The stability of an embankment lies in its ability to resist
shearing stresses created by external applied loads such
as reservoir water pressure and internal forces caused by
the soil mass and embankment slope

16. STABILITY OF DOWNSTREAM
SLOPE DURING STEADY
SEEPAGE
• Examine the most critical condition i.e when the
reservoir is full and the seepage is taking place at full
rate
• Draw the flow net and determine the points of
intersections of equipotential lines with failure arc
• Get the critical arc
• Calculate the shear strength developed on the slices and
find the net shear strength

17. SEEPAGE AND DRAINAGE
 Seepage is the ease at which water flows through the soil
and this is possible due to the presence of voids within
the soil particles.
 Permeability is the property that allows the flow of
water/fluid through the soil.
 The flow of water through the soils is assumed to follow
Darcy’s law:
 Q/t = KAH/l

18. Where, Q = Quantity of water flowing
t = time for quantity Q to flow;
K = coefficient of permeability for the
soil
A = area of cross section through
which the water flows;
H = hydraulic head across soil
l = length of flow path through soil.

19.  Seepage can be effectively study by the use of flow nets
 Flow net is a pictorial representation of the path of flow
through a soil.
 Flow net comprises of
 flow lines and equipotential lines
 Construction of flow net

20. CONTROL OF SEEPAGE
 Through embankment:-
 Rock Toe/filter and
 Horizontal blanket methods
 Through foundation:-
 Impervious cut offs and
 Chimney drain methods

21. PERFORMING MONITORING
 Maintenance – periodic and
 Daily routing maintenance

22. RESERVOIR DESIGN STUDIES
 Types of reservoirs
 Storage reservoirs – To retain excess water flow in a
natural stream or river during raining season
 Service/Distribution reservoir – used in water supply
system where water stored in it is used to supplement the
water supply when the demand exceed the water
pumping rate

23. THANK YOU