A bridge spans a divide such as a river, ravine, or road and allows traffic such as vehicles, trains, pedestrians, or pipes to cross. The main components of a bridge are the superstructure above the bearings and the substructure below. Common types of bridges include slab bridges, girder bridges, truss bridges, suspension bridges, and arch bridges, with the type chosen based on factors like the span length, location, loads, materials, and costs.

3.  A bridge is a structure that spans a divide
such as:
 A stream/river/ravine/valley
 Railroad track/roadway/waterway
 The traffic that uses a
bridge may include:
 Pedestrian or cycle traffic
 Vehicular or rail traffic
 Water/gas pipes
 A combination of all the above

4. Super structure
Sub structure
Adjoining structure

5. The components of the bridge above
the bearing is known as Super Structure.
 Beams, Girders
 Arch, Cables
 Flooring
 Bearing
 Parapet wall, Hand Rail

6. The components of the bridge below the level of
bearings is known as Sub Structure.
 Abutments
 Piers
 Wing walls
 Foundation for
abutments and
Piers

7. I. Based on material used
II. Location of bridge floor
III. As per alignment
IV. Purpose
V. Type of superstructure
VI. According to HFL
VII. According to Spans
VIII. Span Length
IX. Navigation Facility
X. Life of Bridge
XI. As per loadings

8. Based on the type of Superstructure, the types
of bridges are :
1. Slab bridges
2. Girder bridges
3. Truss bridges
4. Suspension bridges
5. Arch bridges

9.  Span of bridges is 3 to 6 m,
slab bridge is used
 It is also called Culvert.
 R.C.C. slab is directly
supported over two strong
abutments
 When the span of bridge is
more
 Flooring is supported on
R.C.C or steel girders.
1. Slab bridges 2. Girder bridges

10.  When the flooring of a bridge is
supported over steel truss
 Normally, such type of bridge are used
for Railways.
 Typical span lengths are 40m to 500m
3. Truss bridges

11.  Suspension bridges consist of sets of cables
hanging in a curve from which the roadway
is supported.
 Three types of suspension bridges which
shown below
A. Simple suspension bridge,
B. Suspension bridge with stiffening truss,
C. Suspension bridge with braced chain.
4. Suspension bridges

12.  Suitable for deep
valley.
 The construction of
piers in the bed of river
is avoided.
 They are light in
weight.
 They are economical.
 There are very few
suppliers of bridge
cables and machined
sockets.
 Painting is essential for
all steel components at
regular intervals.
 The location of the deck
is limited.
Advantages Disadvantages

13.  In such type of bridge the weight of flooring is
transferred to the piers through Arch.
 The floor beam is suspended through hangers
from Arch.
 This type of bridge is used when more
headroom is required below the bridge.
Hinge-less
Arch
Two hinged
Arch
5. Arch bridges

14.  Distributes (spreads out)
compressive forces diverts
weight onto its two abutments
 Tension forces are virtually negligible.
 The greater curvature, the greater the effects
of tensionon the underside of the bridge.
 Modern arches typically span between 200
and 800 feet.
 The ancient Romans built arch bridges and
aqueducts that are still standing today.

15. Choice of Bridge
Superstructure
 The nature of stream or river
 Nature of foundation available
 The amount and type of traffic
 Climatic conditions
 Type of available construction material
 Availability of labour
 Availability of funds
 Time available for construction
 Maintenance provisions
 Strategic consideration
 Economic consideration
 Aesthetic consideration