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2. APPLICATIONS OF
PLATE GIRDERS IN
STEEL CONSTRUCTION

3. Haider Ali Jafferi
Civil Engineer
Hyderabad, Sindh

4. PLATE GIRDERS
 “A plate girder is a type of beam built from plates of
steel that are either bolted or welded together.”
 The plate girders are typically I-beams made up from
separate structural steel plates which are welded or,
bolted or riveted together to form the deep vertical
web with a pair of angles each edge to act as
compression and tension flanges.

7. HISTORY AND BACKGROUND OF PLATE
GIRDERS
 Plate girders became popular in the late 1800's,
when they were used in construction of railroad
bridges.
 By 1950's welded plate girders replaced riveted and
bolted plate girders.
 The purpose of the plate girder is to build a beam
that is larger than anything that can be built by
a steel mill or factory.

8.  The size and shape of the girder allows builders to
construct structures that are much longer and
heavier duty.
 Plate girders are usually prefabricated and the
length limit is frequently set by the mode of
transportation.

9. APPLICATIONS OF PLATE GIRDERS
 Plate girders are usually used to construct bridges
that are suitable for short to medium spans and
may support railroads, highways, or other traffic.
 Some of the most commonly used girder bridges
are:
i. Box Girder Bridge
ii. Beam Bridge
iii. Multi- Girder Composite Bridges
iv. Half-Through Plate Girder Bridges

10. BOX GIRDER BRIDGES
 Box girders are a particular form of plate girder, with
two webs joined by common top and bottom
flanges.
 The box girder normally comprises either
prestressed concrete, structural steel, or a
composite of steel and reinforced concrete.

11. BOX GIRDER BRIDGES (CONTINUED)
Advantages
 Offer better resistance to torsion.
 Gives excellent appearance and durability.
 larger girders can be constructed.

12. BOX GIRDER BRIDGES (CONTINUED)
 San Francisco–Oakland Bay Bridge, aka Bay
Bridge, California, USA

13. BOX GIRDER BRIDGES (CONTINUED)
 Main materials are Steel & concrete
 Total length is 4.46 miles (7.18 km)
 Width is 96.24m
 Height is 526 ft (160 m)

15. CRANE BRIDGE RUNWAY GIRDER
 Crane bridge girder is a special type of plate girder
used to support the crane loads.
 Crane runway girders provided in a perpendicular
direction to the crane bridge at the ends may also
be the plate girders.

16. C. B. R. GIRDER (CONTINUED)
 Usage of Crane bridge Girders has allowed the
engineers to deal efficiently with higher loads.
 Some of the important features of C.B.Gs are:
• Limit the applied stress range to acceptable levels.
• Avoid unexpected restraints at the attachments and
supports
• Avoid stress concentrations at critical locations
• Avoid eccentricities due to rail misalignment or crane
travel
• Minimize residual stresses

18. BEAM BRIDGES
 A beam or girder bridge is the simplest kind of
bridge.
 A beam bridge consists of a horizontal beam that is
supported at each end by piers.
 The weight of the beam pushes straight down on
the piers.

19. BEAM BRIDGES (CONTINUED)
 Beam bridges rarely span more than 250 feet. This
doesn't mean beam bridges aren't used to cross
great distances it only means that there may be a
series of beam bridges joined together, creating
what's known as a "continuous span."

21. BEAM BRIDGE (CONT)
 Esplanade Riel Bridge, Winnipeg, Canada
• Pedestrian bridge
• Designer : Colin Douglas Stewart and Étienne
Gaboury
• 197 meters (646 ft) long & 7m wide

22. MULTI-GIRDER COMPOSITE BRIDGES
 'Composite' means that the steel structure of a
bridge is fixed to the concrete structure of the deck
so that the steel and concrete act together, so
reducing deflections and increasing strength
 One of the most commonly used for medium span
bridges.
 Multi-girder construction is used for single spans
and for continuous multiple spans.
 Effectively used where construction depth is limited.

23. M-G-C BRIDGES (CONTINUED)
 The girders are braced together at supports and at
some intermediate positions
 Generally taken into account, where short piers are
to be used.
 Use of multi-girders allow the designer free to
choose the thickness of web and size of flange
accordingly.

24. M-G-C BRIDGES (CONTINUED)
 River Eden Bridge
• Three span multi-girder bridge
• Main span of 64 m, with 34m side spans
• 1351t capacity

25. M-G-C BRIDGES (CONTINUED)
 Surtees Bridge, at river Tees, United Kingdom
• 150m of total span
• 3 no of spans, 2 piers in water
• About 2000t capacity

27. HALF THROUGH PLATE GIRDER BRIDGES
 A bridge provides a running surface for the traffic
that crosses it and to ensure minimum interface
issues.
 The traffic runs on top of the bridge structure.

28. HALF THROUGH P.G.B (CONTINUED)
 Provide best solution for small and medium span
bridges.
 More commonly seen in railway bridges and
footbridges.

29. HALF THROUGH P.G.B (CONTINUED)
 Preferred, where there is minimum clearance level
above the ground, river, road or the railway below.
 In half through configuration of girder bridge, the
traffic is only partially inside the structural envelope.

30. HALF THROUGH P.G.B (CONTINUED)
 Common solution for pedestrian and cycle-way
bridges.
 The footway/cycle-way is relatively narrow and a
stiffened steel plate deck can easily span between
open web main girders on either side.

31. Half Through Plate Girder Bridges

32. BRIDGES USING PLATE GIRDERS

36. ADVANTAGES OF USING PLATE GIRDERS IN
STEEL CONSTRUCTION
 There are number of advantages of using plate
girders in bridge construction or other structures,
some of which are as follows:
 Possessing the features of structure is simple.
 Provides Convenient Transport.
 Speedy erection.
 Heavy loading capacity,
 Great stability and long fatigue life.
 Being capable of an alternative span, loading
capacity.