This document provides an overview of bridge engineering and its various components. It discusses the types of bridges such as slab bridges, girder bridges, truss bridges, arch bridges, suspension bridges, and movable bridges. It also describes bridge components like substructures, foundations, piers, abutments, and superstructures. Additionally, it covers topics such as bridge selection, investigation, design, construction and maintenance.

1. Prepared For:-
Diploma Sem
4(Civil )
Prepared By:-
Aparna Sharma

2.  Road Engineering
 Bridge Engineering
 Railway Engineering
 Harbour Engineering

4.  Bridge Introduction
 Investigation for Bridge
 Bridge Foundation
 Bridge Sub-structure and Superstructure
 Maintenance of bridges

6.  A bridge is a structure for carrying the road
traffic or other moving loads over a
depression or obstruction such as river,
channel,road or railway.

7.  Road & railway traffic can run uninterrupted in
monsoon.
 Saving in time & fuel.
 It improves aesthetic of a road.
 Distance between two place can be reduced.
 Agricultural & industrial products & raw materials
can reach to the industries quickly which helps in
economic development of the area.
 Construction of a bridge on railway alignment at
level crossing reduces numbers of accidents.
 Bridges are important from military point of view.

10. Substructure
Foundation (Pile/Spread
footing)
Pier (Column)
Abutment
Superstructure
Any structure above
bearing
Wearing surface
Bridge Components

11. Bridge Components

15.  This includes slab, girder, truss, etc. This bears the
load passing over it and transmits the forces
caused by the same to the substructures.

16.  The BEARINGS transmit the load received
from the decking on to the substructure and
are provided for distribution of the load
evenly over the substructure material which
may not have sufficient bearing strength to
bear the superstructure load directly.

20. These are provided as extension of the abutments
to retain the earth of approach bank which
otherwise has a natural angle of repose.

22.  Based on the material used
 As per alignment
 Location of bridge floor
 Purpose
 Types of superstructure
 According to HFL
 According to spans
 Span length
 Navigation facility
 Life of bridge
 As per loadings

23.  Timber Bridge
 Stone Masonry
 Rcc bridge
 Steel bridge
 Prestressed cement concrete bridge
 Composite bridge

24.  Straight alignment: When the alignment of a bridge
is perpendicular to the centre line of a river, it is
called straight bridge or square bridge.
 Skew bridge: when the alignment of a bridge is not
perpendicular to the centre line of a bridge, it is
called skew bridge.

25.  Deck Bridge:-When the bridge flooring is provided
at the top of the super structure,it is called Deck
bridge.
 Through Bridge:-When the bridge flooring is
provided at the bottom of the super structure, it is
called through bridge.
 Semi-Through bridge:-When the bridge flooring is
located at some intermediate level in the super
structure, it is called semi-through bridge.

27.  Aqueduct
 Viaduct
 Grade separator
 Highway bridge
 Railway bridge
 Foot bridge
 Pipe bridge

28.  Slab bridge
 Girder bridge
 Truss bridge
 Suspension bridge
 Arch bridge

29. • The most common and basic type
• Typical spans : 10m to 200m

30. • Truss is a simple skeletal structure.
• Typical span lengths are 40m to 500m.

31. In design theory, the individual members of a simple truss
are only subject to tension and compression and not
bending forces. For most part, all the beams in a truss
bridge are straight.

32.  Arches used a curved
structure which provides a
high resistance to bending
forces.
 Both ends are fixed in the
horizontal direction (no
horizontal movement
allowed in the bearings).
 Arches can only be used
where ground is solid and
stable.
 Hingeless arch is very stiff
and suffers less deflection.
 Two-hinged arch uses
hinged bearings which
allow rotation and most
commonly used for steel
arches and very economical
design.
Hinge-less Arch
Two hinged Arch

33.  A typical suspension bridge is a continuous deck with one or
more towers erected above piers in the middle of span. The
deck maybe of truss or box girder.
 Cables pass over the saddle which allows free sliding.
 At both ends large anchors are placed to hold the ends of the
cables.

34.  Submersible bridge or cause way
Low level causeway
High level causeway
 Non submersible bridge

35.  Simply supported bridge
 Continuous bridge
 Cantilever bridge
 Balanced cantilever bridge
According to span length
 Culvert-span up to 8m
 Minor bridge-8-30 m
 Major bridge-30-120 m
 Long span bridge-above 120 m

36.  Swing bridge
 Bascule bridge
 Traverse bridge
 Lift bridge
 Transporter bridge

43. Temporary bridge
 Pontoon bridge
 Boat bridge
 Flying bridge
 Raft bridge
Permanent bridge
 Rcc bridge
 Masonary bridge
 Steel bridge
 Prestressed concrete bridge

44.  Class AA bridge
 Class A bridge
 Class B bridge

45.  A low coast bridge may be define as bridge
constructed at low cost and capable of being
maintained at low cost.
Reason to construct low coast bridge
 Lack of money, resource
 Lack of time and materials
 Temporary need
 Repairs to permanent works
 Undertaking project surveys in the interiors
 To facilitate the execution of permanent works.

46.  Causeways
 Culverts
 Timber bridges
 Floating bridges
 Flying bridges

48. • Span length
• Bridge length
• Beam spacing
• Material available
• Site conditions (foundation, height, apace
constraints)
• Speed of construction
• Aesthetics
• Cost
• Access for maintenance
Which Type Should I Use?Selection of site

49.  Width of bridge
 A straight reach
 Foundations
 River banks
 Square alignment
 Materials and labour
 Velocity of flow
 Free board
 Minimum obstruction to waterway
 Absence of scouring and silting
 No confluence of large tributaries
 Adequate vertical height

50.  Length of the bridge:- The distance between inner
faces of two abutments is called length of the
bridge.(L)
 The clear distance between two piers or between
abutment and pier is called the clear span.
 Let , there are n numbers of spans.
NO. of piers=n-1
Length of bridge,
L=(n*l)+(n-l)*b
where, l=clear span
n=number of span
b=width of span

51.  Linear water way: The area through which the water
flows under a bridge super structure is known as
the water way of the bridge & the linear
measurement of waterway between the two edges
of the flow of the water, perpendicular to the
abutments is called linear water way.
 Linear water way=sum of all the clear span
 Effective linear water way:
= width of river bed - obstructions to flow like pier
width

52.  Afflux: The phenomenon of heading up of water on
the upstream side of the stream is known as afflux.
= Increased in water level due to obstructions -
Normal water level.
Free board: Free board is the vertical distance
between the designed high flood level, allowing for
afflux, if any , and the level of the bottom of the
bridge girders.
Vertical clearance: They are of two types:
1) Below super structure
2) Above super structure

53.  Below super structure: IT is a vertical intercept
between the lowest level of supporting structure of
bridge flooring and the maximum water level at
time of HFL.
 Above super structure: When vehicle travel on
abridge any projecting part of the vehicle should
not strike with sides or at the top.
 High flood level: it is the level of the highest flood
ever recorded or calculated.
 Formation level: The level of flooring of a bridge
super structure is called formation level.

54.  Scour depth: The term scour used to indicate the
increase in depth in vertical direction of the bed of
river , such increase in depth in mainly due to the
currents of flowing water. The bridge foundations
should be taken beyond the depth of scour.
 Economic span: The economic span of a bridge is
the one which reduces the overall cost of a bridge
to be a minimum.
 Thus most economic span length is that which
satisfies the following,i.e,
The cost of the super structure=The cost of the
substructure.

56.  It consist of the following :
 Piers
 Abutment
 Wing wall
 Approach
 Foundation

57.  Solid pier
 Dumb bell
 Column pier
 Cylindrical pier
 Abutment pier
 Pile pier
 Trestle pier
 Cellular pier

58.  To transfer the load of the superstructure to the
soil through foundation.
 To divide the bridge length into suitable spans.
Function of weep holes:
 Weep holes are provided to drain off water which
gets access to the earth filling.

59.  The end support of a bridge super structure is
known as an abutment.
Function :
 To finish up the bridge so that it can be put for
use.
 To retain the earth filling.
 To transmit the reaction of superstructure to the
foundation.

60.  The device which are provided over the supports
of the bridge to accommodate the changes in the
main girders due to deflection, temperature,
vertical movement due to shrinkage, creep.
prestressing etc ,and to transmit the load from the
superstructure to the substructure are known as
bearings.

61.  To absorb movement of girders.
 To distribute load on large area.
 To simplify the procedure in design.
 To keep the procedure in design.
 To keep the compressive stress within limits.
 To transfer horizontal forces due to braking.

62. Bearings
For steel &
Iron bearings
Fixed bearings
1)Shallow plate
bearing
2)Deep base
bearing
3)Steel hinge
bearing
4)Rocker bearing
5)Laminated
rubber bearing
6)Cement mortar
pad bearing
Free bearings
1)Sliding plate
bearing
2)Rocker type
bearing
3)Roller
bearing
For concrete bearings
a)Bearings for slab
bridge
1)Tar paper bearing
2)Laminated copper
bearing
b)For girder bridge
1)Lead bearing
2)Rubber bearing
3)Slide plate bearing
with curved top plate
4)Neoprene bearing
5)Bearing for
submersible bridge

64. Factors affecting deterioration:
 Defective design of bridge
 Poor quality of construction materials
 Poor quality control during construction
 Effect of water on the parts in contact with water
 Resistance to weathering effects
 Temperature changes
 Movement of vehicles heavier than the design load
 Miscellaneous factors like flood,earthquake,etc.
 Negligence to minor defects.

65. Various inspection were carried out to prevent
deterioration are:
 Inspection of foundation
 Inspection of substructure
 Inspection of superstructure
 Inspection of approach road
 Inspection of bearings
 Inspection of waterway
 Inspection of protection works
 Inspection about scouring

66.  Weakening of foundation : In such case, the bridge
should be closed for traffic. By underpinning
technique the foundation should be strengthened
by providing grillage foundation or pile foundation.
 Erosion of foundation: If erosion is substantial,
urgent repair is required. The soil surrounding the
old foundation is excavated and new concrete bed
is provided. If depth of scour is more sheet piles
are driven around the old foundation.

67.  Damage flooring and approaches: In case of
cement concrete road , if the wearing surface of
road is worm out due to heavy traffic and
reinforcement bars are visible , it is visible to
provide a new layer of cement concrete or
bituminous concrete.
 Defects in bearings: For effective functioning of
bearing following care is to be taken:
 Cleaning of bearing regularly
 Regular lubrication
 There should not be cracks in the bearing
 It should be free from corrosion.

69. Purpose of inspection report:
 To get the information regarding damage to the
various components.
 To prepare an estimate of repair
 To know the cause of damage
 To decide the importance of works of repair
 To make arrangement of funds for repair
Necessity of inspection report:
 Inspection report is necessary to decide the
requirement of skilled and unskilled labours
machinery machinery and equipments.
 To make alternative planning for diversion of traffic
in advance.

71.  Railway Introduction
 Points, crossing and Yards
 Maintenance of railway tracks

72.  Rail transport is where at rain runs along a set of
two parallel steel rails, known as a railway or
railroad. The rails are anchored perpendicular to
ties(or sleepers) of timber, concrete or steel, to
maintain a consistent distance apart, or gauge. The
rails and perpendicular beams are placed on a
foundation made of concrete, or compressed earth
and gravel in a bed of ballast.

73.  It facilitate long distance travel and transport of
bulky goods which are not easily transported
through motor vehicles.
‡
 It is a quick and more regular form of transport
because it helps in the transportation of goods
with speed and certainty.
 It helps in the industrialization process of a
country by easy transportation of coal an draw-
materials at a cheaper rate.Ballast

74. rail
sleepers
Ballast

76.  The clear horizontal distance between the
inner faces of the two rails forming the track
at the top is called the gauge of the rails.
 There are four types of the gauges in india.
 Broad gauge(B.G.)=1.676m
 Metre gauge(M.G)=1.00m
 Narrow gauge(N.G.)=0.762m
 Light gauge(L.G.)=0.610m

77.  Gauge to be used in particular country should be
uniform throughtout as fsr as possible,because it
will avoid many difficulties.
Advantages
 The delay cost and hardship in transhipping
passengers and goods from the vehicles of one
gauge to another is avoided.
 As the transhipping is not required,there is no
breakage of goods.
 Difficulties in loading and unloading are avoided
and labour charges are saved.

78.  Points and crossing are special arrangements
provided on railway tracks for enabling trains to be
diverted from one track to another.
 It provided flexibility of movement by connecting
one line to another according to requirements.
 They also help for imposing restrictions over turn
outs which necessarily retard the movements.

79.  A railway station is a place on a railway line,where
trains stop for clearing passengers and goods
traffic.
Purposes of railway stations:
 For exchange of passengers
 For exchange of goods
 For control of train movements
 To enable the following express trains to overtake.

80.  A yard is a system of tracks laid usually on a level
within defined limits, for receiving, storing, making
up trains, dispatch of vehicles and for other
purposes over which movements are not
authorized by a time table.

81.  An adequate number of plateforms should be
provided so that all trains can be dealt with at the
same time.
 There should be convenient sidings where extra
carriages can be stabled after having been
detached from trains
 Unless all trains are booked to stop at the station,
it should be possible to run a train through the
station at a prescribed speed
 Washing lines, sick lines, stabling lines, etc should
be provided at the station yard.

83.  HARBOUR:
◦ SHELTERED AREA
◦ FOR LOADING AND UNLOADING OF CARGO
◦ VESSELS ARE ALSO BUILT, REPAIR, AND LAUNCH

84.  CLASSIFICATION:
1. NATURAL HARBOUR
2. SEMI NATURAL HARBOUR
3. ARTIFICIAL HARBOUR

85.  NATURAL HARBOURS:
A harbor, is a place
where ships, boats, and barges can seek shelter
from stormy weather.

87.  SEMI NATURAL HARBOUR:
Same as natural but harbour needs
some artificial and man made construction

88.  ARTIFICIAL HARBOUR:
Harbour having no natural protection but
artificial arrangement are made to protect the
harbour from storm and wind.

90.  REQUIREMENTS OF A GOOD HARBOR:
◦ The depth of a harbor should be sufficient for
every type of visiting ships.
◦ The bottom of harbor should provide secured
anchorage to hold the ships against high winds.
◦ To prevent destructive wave action, break water
are provided.
◦ The entrance of a harbor should be wide enough
to provide the easy passage of ships.

92.  DEFECTS IN HARBOR:
◦ Depth of water is found insufficient for different
ships.
◦ The size of harbor is found insufficient to
accommodate the increased traffic.
◦ Obstruction
◦ These defects can easily be avoided at the time of
planning and designing.

93.  SIZE OF A HARBOUR
Size depends upon:
 of ships
 length:275m-300m
 width:30m

94.  HARBOUR PLANNING
It should be carried out after collecting necessary
information of the existing features at the
proposed site.
 Following important facts should be studied.
 A thorough survey of the neighborhood including
the foreshore & depths of water is necessary
 Nature of a harbor wether sheltered or not, be
studied
 The existance of sea insects & various animals
residing at site.

95.  Natural phenomena’s concerning planning of a
harbour are:
 Storms
 Rainfall
 Range of tides
 Maximum & minimum temperatures
 Direction & intensity of wind etc

96.  SITE SELECTION:
Following factors play a great role in
the choice of site of a harbour.
1.Availability of cheap land & construction material.
2.Natural protection from waves & winds
3.Transport & communication facilities
4.Industrial development of the locality
5.Sea bed,sub soil & foundation conditions
6.Avaibility of electrical energy
7.Defence & strategic aspects
8.trafic potentiality of harbour

97.  FUNCTIONAL CLASSIFICATION:
1. HARBOR OF REFUGE
2. COMMERCIAL HARBOR
3. FISHRY HARBOR
4. MILLITARY HARBOR OR NAVEL BASE

98.  HARBOR OF REFUGE:
The harbor used for ships in
storms or emergency condition good anchorage
and safe and easy access from the sea.
e.g: DOVER IN ENGLAND

100.  COMMERCIAL HARBOR:
Facilities for loading and unloading
of cargo are provided.
The may be:
1. Part of bigger complex harbor
2. Independent unit or single
commodity harbor.
3. Terminal as oil terminal, coal
port.

102.  FISHRY HARBOR:
Provided for fishing crafts and trawlers.

103.  MILLITARY HARBOR:
This harbor is meant for accommodating
naval crafts and serves as a supply deport.
The layout of this type of harbor is
greatly influenced by its location.

105.  FEATURES OF A HARBOR:
1. Entrance Channels
2. Berthing Basin
3. Break Water
4. Turning Basin
5. Pier Head
6. Wharves
7. Jetties

106.  ENTRANCE CHANNEL:
◦ Depth and width are kept more at entrance
◦ Width depends upon density of traffic and no: of
entrances

107.  BERTHING AND TURNING BASINS:
◦ Berthing basins are used for the parking of ships
◦ While turning for the turning of ships

108.  BREAK WATER:
◦ The structure constructed to protect harbor from
storm waves
◦ They are generally stone masonry

109.  PIER HEAD:
◦ The structure provided at the tip of break water
◦ Such as light house

110.  WHARVES:
◦ The structure constructed parallel to the shore or
break water, having wide plate form at the top
◦ Function is to permit berthing of vessel along side
for cargo working

111.  JETTIES:
◦ Same as wharves.
◦ Used for loading and unloading of cargo.
◦ Made usually from shore towards sea water to
prevent silting and dredging to allow free flow of
tidal currents.

113.  DOCK:
◦ A dock is dug out and usually has gates so that the
water level is kept up even though the tide has
gone out.
◦ A dock is for mooring ships for cargo or passenger
exchange, or sometimes repair.

114.  HARBOR:
◦ A harbour may be natural or partly dug out, or
even made with floating materials. It doesn't have
gates, but may have a narrow entrance.
◦ Provides safe anchoring or mooring for ships

115.  PORTS:
◦ A port is a location on a coast or shore containing
one or more harbors where ships can dock and
transfer people or cargo to or from land.