Structure

Bridge

Components
Highway

Loading

Components
Live
Bearing Piles
‐ ‐ ‐
3 6
Bridge

Stringer
Footing Embakment 9 Basic
‐ ‐ ‐
and 2

Pedestal 5 Underpass 8
Deck
‐ ‐ ‐
1 4 7

6-Footing & piles 7-Backfill 8-Approach 9-Embankment

Components

Bridge

Basic
1-Deck & wearing surface 2-Primary member 3-Joints 4-Bearing 5-Abutment

bridge

of

components

the

all

comprises

supports.

the

superstructure

Superstructure The above

from
51

a to

is

(13 it of
cross

in thickness

2
in
deck
cases to
made

the 1/2
varies

other layer of

.
usually some typically

is wear portion in

separate

deck. a

course
Components that is

while traffic
is surface
,
mm). this

wearing concrete
Concrete 102
resists
surface
of wearing to

material

(51 instances
part Surface.
which
in Modified

integral 4 bituminous
wearing

to some
The Latex 2 mm). The
Superstructure The In
section bituminous integral
  
Wearing
 
■
Basic

(Asphalt)

Material

An asphalt Layer which have less voids and high surface resistance Asphalt
concrete overlay rests on top of the deck. Asphalt concrete layer ranges from 2 to
4”. It is recommended that to roughen its surface prior to placement of the
asphalt concrete overlay
    Wearing Surface Bituminous

admixture
a latex emulsion
, and
).
aggregate
,
cement
Concrete

:
styrene butadiene
Modified

Less porous Resist thermal forces caused by temperature changes. Used to replace
the wearing surface of existing bridge decks. Less depth than asphalt concrete .
Latex modified concrete layer ranges [1.5 in (38 mm)]. It is recommended that to
the concrete deck surface should be blast cleaned and wetted It is composed of
(such as
Advantages    
Wearing Surface Latex   

Concrete

Modified

Wearing Surface Latex

across

loads

roadway

the

section. distribute
of

to

is
cross

deck Components

extension

bridge
bridged.
the

of the be

to
physical

along
the

function is

deck main obstruction

Superstructure

The the The transversely

 
Basic Deck

. plate
some are
slab

or
or steel
shear and
deck

and the geometry timber,

the stringers stringers,

flexure
deck.
between
longitudinally adjust laminated
flange called

to
resist

also placed wide

 loads glued finished
to

be
Components the stringer
steel

can
be
and the

members
distribute of

principally

could
haunch
beams. stringer
or
flange
of
primary

the
top members prestressed concrete, fillet

stringers designed
type
type
Members the

small
Superstructure
These between and A other girders,
Primary usually Beam girders.
 
 
Basic Primary

sectional deformation
‐
Components

Members.

Superstructure

Secondary members are bracing between primary members designed to resist cross
of the superstructure frame and help distribute part of the vertical load between
stringers. Secondary members, composed of crossed frames at the top or bottom
flange of a stringer, are used to resist lateral deformation. This type of
secondary member is called lateral bracing
  
Basic Secondary
superstructure

the

support

6.
to

to

required
Items

elements roadway.

all

of

overpass

Consists and
Substructure

to

to
the

and cast

be single,
component
of: adjacent a

designed each support

can
It at and
. form
beginning

primary
consists which

the
backwall,
the
at is
structure

abutment
always
backwall to
 underneath

the stem,
structures
abutment

roadway retaining the

earth a
the

behind as abutment
to
Abutments
called
Components retaining
‐ the
wall
earth overpass
acting
retaining

with It
side earth
and
a
roadway.
structure.
is
are sometimes
confining
abutment in bridge.

the

of approach

assist monolithically of Backwall integrated approach. Wingwall

Substructure

Abutments end superstructure the

 

Abutments Basic

Components

Walls
Wing
with
Substructure
Abutment
abutment
‐
U Gravity
Abutments Basic
in

at

(abutments)
sizes

and

superstructure

supports

the

shapes

end

of

the

support
Components

variety

which

in between

come
points

structures
and

Substructure
are

span

Piers
long intermediate Piers  Basic

are

only

vertical
rotation
substructure, the translation

the

the

allow

to

transmit

between

which

longitudinal

which

and
those

superstructure and

movements

systems
Components
substructure. the rotation

of

the

both
bearings,

bearings. and
loads

mechanical

fixed

allowing are

expansion

Substructure accommodate/adjust horizontal

called

and superstructure Bearings and called are Bearings

  Basic
Bearings.
is
bearing
a
stringer
pedestal.
under the

flange
member. to

pier
or wide

primary the
attached

is
abutment
turn
cutaway, an
in

on
Components superstructure

which a

abutment
column
left
bearing
supports short

the a
the

at is

to
directly
Substructure shown

As Pedestals. which attached

 
Basic Pedestals

in
the
so
for extend

the or
footing.
which
support
from
substructure, piles,
bedrock. spread
stability, a
of to
loads the
cap.
adequate or to
use

called overall
pile
the is a
layer
transfer loads

as provide

soil
piles
capacity,
through
footings known
cannot piles.

is
stronger Components without or
pier
a
bearing
superstructure
soil piles obtained to
of footing and

is a
by by the
subsoil

terms the
footing
under
(in to support
transfer abutment
the
soil
supported supported
the
the from
Substructure
do
bearings
footing footing
substructure As When turn settlement), down substructure A A
    Basic
Piles.
Footing
in
are

which sheeting

of walls
structures.

planks
forms

smaller
retaining
vertical for

common the
sheeting.

as
temporary most

as abutments

the
Components as known
act excavation,
of
to
are
used one

be
shallow are

ground
or
even
piles the excavation

can
into
sheet
Substructure and

cofferdams
permitting In driven Steel use
 
Basic Sheeting

Features

in

8
major
overall the
 a
provide
to
covered which the Related
(Item
‐ not is
in
and
is ‐
Site which
. control

which abutment
purpose
guardrail).
pleasing protection),
site the

and
(e.g., some erosion

(slope Protection from

bridge
and
or serves
(embankment)
Slope called aesthetically structure
tapers

the and bridge

called drainage
both that

of
the be
1.2). material
component
of a
slope
proper

part
with Figure should for underpass The
Appurtenances
 Any Embankment structural functionality

and
from steel
which
from
than
Features away

structure
drivers
 and
rather
corrugated abutment, the
to

of an
roadway shield
up
roadway. in
from of to
railings

made Related
leads
side ‐
away used
rail

bridge
approach
which underdrain
either
Site runoff
device guard the
an
a called

along channels.

called roadway from

and install
parapets. is
usually
transports to
protective
vary a located
are
drainage
is
can overpass
concrete
system they slope
of
abutments
necessary or
barrier

barriers barriers.

appropriate section often bridges, bridge

drainage
reinforced traffic a
is Barriers
A On
It The is obstacles the into Traffic to traffic
    
Underdrain Approach Traffic
Appurtenances
 16
can
are
after of

that AASHTO

surface,
pedestrians,
hardens
loads structure
clearance
slab
wind, the wearing
loads.
underpass.
on
design
a the dead allowable

concrete
vehicles,
and and placed
sidewalks, total as
the

m) of

loads such maximum rating.

railing, part
before
structure the
ft (4.27
load
a the 14

bridge
of structure,
permanent
structure
compute considered called a
the (e.g.,
are is
to between
on
on
minimum
loads
bridge loads.
Te r m s
placed a hardened placed
distance
structure Loads
live dead are generally
a
has
 absolute
loads. loads of
loads are
across
Dead an
called
m).
dead Bridge minimum
They
are
concrete analysis
carried Clearance
the

be called etc.). specifies Is An Permanent Superimposed Temporary the etc., ft

(4.88 Loads
Rating
Loads
    
Other
Vertical Load Dead Superimposed Live

the
by
structure
the

affected
of
is
end
the

crossing
to
soil. workers
bridge.
crossed

given of
start bed
environment be a

funds.
its to at
the
Types
unskilled
and
and
alignment conditions
used from required
and ravine

be construction
river or
surrounding
to
for
the skilled materials
the bridged overpass

of of of clearance
of of
be
channel temperature
Structure
to
of structure

available

nature factors of

Underpass Extreme The Depth Length Aesthetics Curvature Availability Availability

Time
type
          Bridge
following The

to
create
with on
span of

to
and

short
forms resting
covered

thicker for

diaphragms
be slab
other
geometry by

can made
prestressed concrete
‐ the is

primarily
concrete and
which
a are together excessive, itself

precast
of
slab,
slab
requirements.
the excessive
the become
beams, however,

of consists connected

site
top a steel are surface

clearance become of
be investigated.
the

sometimes materials. structures,

be which

wearing over could

lengths average
superstructure
other Stringer must
‐
surface, constraints stringer or
and ‐
frame. span
passes on stringers,
a ‐
on
stringers bridge ‐
of integrated

When structures physical lengths girders, Traffic Slab form The an set wearing The
Slab

1.     

or a

of

slab,

together wearing

of girders, the
wearing
beams,
made a
of consists
set
is frame.
a
a
top steel
with
on
connected itself integrated
be
the
form
an
are
slab to

resting over covered could

Stringer
‐
the superstructure
be
create which
slab on
prestressed concrete ‐
to ‐
passes can
materials.
stringers bridge
diaphragms
Slab

Traffic other which precast The by stringers, concrete surface thicker The surface,
sometimes
1.
   

or
a

of is design readily

clean
of a

use and

uniform deteriorated
economy simplicity
a

an to
makes
that

for erection

wideflange stringers and

repairing
in are:
quick
steel
consistent
provide ‐
for
understood like
self

time system a be

allow employed is

easily.
straightforward this be
same

should members of

beams can bridge It

the

at
relatively
primary
is standardized
design. stringer
while ‐
methods
of be
on
advantages materials.
‐
term.
Stringer
can ‐
slab
on
‐
Construction Prefabricated The Simplicity available Economical which structures.
appearance materials. prestressed concrete relative
principal

     Slab

The
1.

of

Girder albeit Most major

structure are

Box
requirements.
place.
‐
type in pleasing,

span
torsion
cast posttensioned.
girder
long and or

are Concrete

box
solution.
a
aesthetically
,
and
precast
bending an bridges
relatively
be
Steel
these Can Meet offers expensive, When concerns
2.
  

to
(150

from

lengths

bridges.
span
length
with stayed
‐
cable
bridges
significant as

of

modern
long spans
major of of

constructed and
the popular with
construction,
type a

of are

been number
this

now
medium ease
is
Stayed have why
‐ presented
for
bridges. m)
cost, aesthetics

significant

900 When A
Cable span choice structure reasons and Low

  3.


Stayed
‐
Cable

3.

an

impressive offers

over
bridge task.

length
suspension
engineering
significant the

of
rivers),
spans
monumental
a (e.g.

with
to
obstacles answer

presented
Suspension elegant physical When

 4

Suspension

4
is
deck

the
a

in
arch,
supports.
pier structure called
either
tied a
attractive is
end is a

the
an for its of

this
at for
forces arch,
case
need
arch,
the the forces steel

the provide
in
reaction the of
or

top
reaction arches supports.
from these

on
eliminating
of
Arch.
arch large steel

also
foundations, the

suspended
supported while
is site, arch.
between
is component
generates
Concrete
tie

a abutment deck,
deck
by by and bridge through structure
 the
particular the a

horizontal
arch
this
Steel When The
When called resisted river. resisted looking arch. An In
.

    5 

Arch

Concrete

Arches

and

Steel
Steel

, concrete, with its

. .
The tied arch
The two hinged arch
Arch
short to long span bridges
Arches

Concrete

convert most loading into compressive forces

and

The hinge-less arch

The three-hinged arch Concrete
Steel

excellent compressive strength, is an ideal material for these types of structures.

Concrete arches can range from Since arches
5.

.
piers and girder are one
Frame:

. Rigid

-shaped frame -shaped frame Concrete

π
‐ A rigid frame bridge is one in which the solid structure Though there are many
possible shapes, the styles used almost exclusively these days are the pi-shaped
frame, and the V shaped frame
Ve e 6

and

truss

no whole

is
the because
construction

there fail,

the
over,
is
(i.e.,
that
is
high. member itself

of
one very
members

are
unpopular
should
structure critical

so
bridges
becomes bridge
path,
fracture it
truss

new of
load
a
collapse).
reason as the

typically costs

in
are would truss
major

steel
Truss

Another structure redundancy members The maintenance

7
 

Temperature changes . Deflections caused by live loads. Creep and shrinkage of

concrete.
Bridge deck joint allow a bridge to expand and contract due to a number factors as
:   
Deck Joint A gap between two spans, or the approach and a span, which allows for
some rotation and/or translation. Why do we need joints? Why do we need joints?
Deck Joint Types

joint
seal
joints joints

joints
joints
plate plate
Joints Joints
Seal
Filled Strip Open Compression Sliding Modular Finger
‐ ‐ ‐ ‐ ‐ ‐ ‐
1 2 3 7 5 6 4
Deck Joint Types

Deck Joint Types :

Open joints are rarely used in new structures and are predominately found
An open joint is nothing more than an opening between the concrete deck and an
adjacent structure element (e.g., deck/deck, deck/abutment). in older, short span
bridges.
covers the gap between the deck and associated structure element. A 1- Inability
to prevent leakage. 2- Susceptibility to deterioration.
A closed joint : closed joint is typically comprised of a sealant and (if needed)
mechanical system to provide for movement at the joint.
Deck Joint Types: 1- Open Joints
  Disadvantages of open joint:

1- short span bridges requiring small joint movement 2- in rehabilitation work “

repair of a damaged joint “.
5-10 years.
Age of Filled joint : Deck Joint Types: 2- Filled Joints
Used in : 1- Quick and easy installation 2- Inexpensivness 3- Performed by house
maintenance Team.
Advantages of Filled joint:

Deck Joint Types: 2- Filled Joints

Deck Joint Types: 2- Filled Joints

Movement Range: 12 mm to 63 mm
1- short span bridges requiring small joint movement 2- In rehabilitation work “
repair of a damaged joint “.
A compression seal consists of an elastic material which is squeezed into a joint
opening coated with an adhesive lubricant.
Age of Compression seal joint : 10-15 years. Deck Joint Types: 3- Compression Seal
Joints
Used in : Disadvantages of Filled joint: 1- Suffer from the constant wear of
traffic and the accumulation of debris. 2- Loosening of the bond between the seal
and concrete surface. 3- The seal above the deck surface where it can be damaged by
traffic


Deck Joint Types: 3- Compression Seal Joints

Movement Range: More than 100 mm

The most popular material (neoprene gland as the sealant). The strip seal is
mechanically fitted to its steel rail assemblies
An elastomeric material which is placed between dual steel rails that are anchored
to the face of the joint opening.
   Age of Compression seal joint : 10-20 years.
Deck Joint Types: 4- Strip Seal Joints

Deck Joint Types: 4- Strip Seal Joints

t
curved
y
Movement Range: can accommodate movements in ranges upward of (0.9 m) and even (1.2
m)
oints which can accommodate varied deck movem
j
oint utilizes multiple (two or more) compression or strip seals
j
oints also represent an attractive solution for horizontall
j
es which demand
g
rid
Each joint rolled beams is supported by individual support bars All joint rolled
beams are supported by the same supporting bars Suffer from fatigue cracks due to
the poor detailing and the dynamic nature of the loading. . Modular A modular b
accommodate very large joint movements.
Deck Joint Types: 5- Modular Joints  Age of Compression seal joint : 15-25 years.

Types: 1- Multiple support system: 2- Single support system : Disadvantages of
Filled joint:

Multiple support system

Deck Joint Types: 5- Modular Joints

Deck Joint Types: 5- Modular Joints

Deck Joint Types: 5- Modular Joints

or bicycles
.
clogged with debris
cause problems for motorcycles
passing over a bridge, especially if there is a rotation or differential
settlement between the both sides of the joint. Finger plate type joints consist
of steel plates which are married together through extending fingers.
Movement Range: allow for movement up to (609 mm)
Disadvantages of Filled joint: 1- The trough can easily become Deck Joint Types:
6- Finger plate Joints 2-The joint surface can


Deck Joint Types: 6- Finger plate Joints

.
, like that described for finger plate joints , is still required
Deck Joint Types: 7- Sliding Plate Joints
A sliding plate is similar to a finger plate joint, except that in place of
meshing fingers is a single plate attached to one side of the joint Movement Range:
Permit movement of up to (101 mm) A Drainage trough to drain runoff and protect
substructure elements.

Deck Joint Types: 7- Sliding Plate Joints

associated therewith.
costs
play an important role in the overall performance
of the selected joint and the
deck the joints
Chemical attack from gasoline, oil, and salts Snow plow damage Structure
deflections across the joint Poor design and installation Traffic pounding
Movement in excess of system capacity
     
So that Expansion joint Failures caused by : maintainability of a bridge. In
making this decision, designers need to weigh heavily the