introduction to bridges

1. Bridges Overview
Faculty of Engineering
Civil Eng. Dept.
By: Dr. Ezzat El-sayed G. SALEH

2. Bridge Overview

3. Types of Bridges
 Typebymaterialof construction
 Typebyuse
 Typebystructure
 Fixedor movable bridge

4. Span of Bridges
 Shortspan: 6 – 30 m
 Medium span:30 – 100 m
 Longspan: > 100 m
 Span > 6m: Bridge
 Span < 6m: Culvert

5. 1. Stone bridges
2. Timber bridge
3. Reinforced concretebridges
4. Prestressed concretebridges
5. Steelbridge
6. Aluminium
7. Composite
Types Material of Construction

6. Types Material of Construction





7. 1. CarTraffic ‫ات‬‫ر‬‫يا‬‫س‬‫ل‬‫ا‬‫حركة‬
2. Pedestrian ‫شاة‬‫للم‬
3. Double-decked.
4. Train bridges ‫ات‬‫ر‬‫للقطا‬‫باري‬‫ك‬
5. Viaducts. ‫سو‬‫كج‬
‫ر‬
Types by Use

8. Types by Use





9. • Arch bridge
• Beam / Girder Bridge
• Cantilever bridge
• Truss
• Tied archbridges
• Suspension
• Cable stayed
Type by Structure

10. • These bridges uses arch as a main structural component (arch is always
located below the bridge, never above it). They are made with one or
more hinges, depending of what kind of load and stress forces they
must endure.
• Typical Span Length 130 ft – 150 ft
Arch Bridge

11. • Very basic type of bridges that are supported by several beams of various
shapes and sizes. Typically consists of a beam simply supported on each
sidebyasupportand canbemadecontinuouslater
• Inexpensivetobuild
• Typicalspanlength30to 650ft
Beam / Girder Bridge

13. They support their load not through vertical bracing but through
diagonal bracing.Theyoften usetrussformation both below and
abovethe bridge.
Cantilever Bridge
Firth of Forth Bridge, Scotland 521m span

14. Reaction Force Reaction Force Reaction Force

15.  All beams in a truss bridge are straight. Trusses are
comprised of many small beams that can together support an
amount ofweight and spangreat distances.
 Typical Span lengths: 40 m - 500 m.
Trusses Bridge

16.  Bridges that use ropes or cables from the vertical suspender to
hold the weight of bridge deckandtraffic.
Suspension Bridges

18. Bridge that uses deck cables that are
directly connected to one or more
vertical columns. Cables are usually
connected to columns in two ways –
harp design (each cable is attached
to the different point of the
column, creating harp like design of
“strings” and fan design (all cables
connect to one point at the top of
the column).
Cable-stayed Bridge

20. • Fixed – Majority of bridges are fixed, with no moveable parts to
provide higher clearance for river/sea transport that is flowing
below them. They are designed to stay where they are made to
the point they are deemed unusable ordemolished.
(
‫تعترب‬
‫غري‬
‫صاحلة‬
‫تعامل‬‫لالس‬
‫و‬‫أ‬
‫هدمت‬
)
FixedorMovable Bridges

21. • Moveable – A movable bridge is a bridge that has dynamic moving
parts used to change the form of the bridge, usually to allow
passage for boats. There are many types of movable bridges,
andthey differ in the way they transform.
FixedorMovable Bridges

22. SimpleSpan
ContinuousSpan
CantileverSpan
BasicSpanTypes

23. ComponentsofaBridge
 Superstructure or Bridge deck- the horizontal part of a
bridge that support pedestrian or traffic activities,
 Bearings - transmit the load received from the decking on
to the substructure,
 Substructure:
 Piers, or Abutments: Vertical member support the deck
or bearing,
 Foundation – transmits the loads of Superstructure,
Piers or Abutments evenly distribute the load on to the
strata.

24. Components

25. Thecharacteristicsof anidealsitefor abridgeacrossariver are:
a. A straight reach of theriver.
b. Steady river flow without crosscurrents:
c. A narrow channel with firmbanks
d. Suitable high banks abovehigh floodlevelon eachside.
e. Rock or other hard in erodible strata close to the river
bed level.
g. Absence ofsharp curvesin theapproaches;
h. Absence of expensive river trainingworks;
i. Avoidance of excessive underwaterconstruction
SiteSelectionforBridge

26. Somepointsthat shouldkeepinmindwhiledesigningthebridge:
• Must carryown weight andweight of traffic
• Must withstand forceof high winds
• Must consider effects of contraction and/or
• Expansion due totemperature changes
Construction

27. The End

28. LOADSON BRIDGES
• Permanent Loads: remain onthe bridge for an
extendedperiodoftime(selfweightofthebridge)
• TransientLoads:loadswhicharenotpermanent
-gravity loads due to
vehicular, railway and
pedestrian traffic
- lateral loads due to water and
wind, ice floes, earthquake,
etc.

29. VEHICULAR LOAD
All road bridges in India are designed in accordancewith “INDIAN ROAD
CONGRESS”specifications.
IRC:5-1998 ,IRC:6-2000 {INDIAN ROADCONGRESS}-
• This model consistof-
• ClassAAloading
• TrackedVehicle
• WheeledVehicle
• ClassAloading
• ClassB loading

30. CLASSAA
LOADING

31. CLASSA
LOADING

32. CLASS B
LOADING

33. LONGEST SPANBRIDGE
Akashi kaikyobridge
ngth
stspan
ncebelow
Suspensionbridge
3,911metres
(12,831ft;
2.430mi)
282.8metres
(928 ft) (pylons)
1,991metres
(6,532ft;
1.237miles
65.72metres
(215.6ft)

34. Longest Bridge
•Danyang–Kunshan GrandBridge
Total length
164.8kilometres
(102.4mi)
Carries
Locale
Rail
China’sJiangsu
province

35. Highest Bridge
•MillauViaduct
ign Cable-stayedbridge
al length 2460m
th 32.05m
ght
343m (max pylonabove
ground)
gest span
mber ofspans
arancebelow
342m
204m, 6×342m, 204m
270m (890ft)