8/2/2019 40609 Types (1)
1/27
Bridge Design
II. Brid e T es
Praveen Chompreda
Mahidol University
First Semester, 2007
Com onents of Brid e
Substructure
Superstructure
Foundation (Pile/ Spread Footing)
Pier (Column)
Any structures above bearing
which support the roadway
Wearin Surface
deck bearings
abutment
foundation
Com onents of Brid e
Superstructure Roadway Deck
Abutment Abutment
uperstructureRoadway Deck
Pier
Abutment
Substructure
Com onents of Brid e
Bearing
8/2/2019 40609 Types (1)
2/27
Com onents of Brid e
Pin Joint
Bearing
ap eam
Com onents of Brid e
Su erstructure
Ca Beam
Bearing
Pier
S an Len th
span length
single span
spanmu span
Span > 6 m Bridge
S an < 6 m Culvert
Short span: 6-30 m
Medium span: 30-100 m
Long span: > 100 m
ypes o r geTypes by Kinds of Traffic
Types by Traffic Position
T es b Material and Fabrication
Types by Structural System
8/2/2019 40609 Types (1)
3/27
T es of Brid e b Traffic
Highway bridge (trucks, cars)
Pedestrian bridge (pedestrians, bicycles)
Railwa brid e trains
Transit guideway (city trains, monorail)
, , , ,
structure)
T es: Hi hwa Brid e
Golden Gate Bridge
California, USA
Avon Mouth BridgeBristol, UK
T es: Pedestrian Brid e
El Alamillo BridgeSeville, Spain200m span
Paris, France
100m span
T es: Railwa Brid e
Mountain Creek Brid e 1880
Canada
Canada
325ft span
8/2/2019 40609 Types (1)
4/27
T es: Transit Guidewa
BTS SystemBangkok, Thailand
T es: Others
oman que uctSpain
Pont du Gard (Roman Aqueduct) (circa 19 BC)
Nimes, France
T es: Others
Runway at the Los Angeles International Airport (LAX)
Los Angeles, USA
T es: Others
Navigational Canal
Netherlands
8/2/2019 40609 Types (1)
5/27
T es of Brid e b Traffic Position
Deck type
Structural components under the deck
Preferred by drivers (can clearly see the view)
Requires space under the bridge
Through type
Structural components above the deck
Obstructed view (not a problem for railway bridges)
No structure under the bridge
Half-through type
T es: Deck T e
Rhone Bridge
Henry Hudson Bridge (1936)
rance
T es: Throu h T e
Firth of Forth Bridge (1890)
521m span
T es: Throu h T e
Tonegawa River Bridge (1972)
apan
8/2/2019 40609 Types (1)
6/27
T es: Half-Throu h T es b Material & Fabrications
Materials
Fabrications
Masonry (brick, rock)
Timber
Precast (RC/PC)
Cast-in-place (RC/PC)
Prestressed Concrete (PC)
Iron
Posttensioned (PC)
Prefabricated (steel)
Steel
Aluminum
Rivet (steel)
Bolted (steel/ timber)
Composites
Plastics
Welded (steel)
Etc
T es b Material & Fabrications
Timber Bridge
probably built in place?
T es b Material & Fabrications
Leonardo Da Vinci Bridge (2001)
Norway
40 m Span
Glue-laminated Timber Bridge
8/2/2019 40609 Types (1)
7/27
T es b Material & Fabrications
Steel
Prefabricated
(probably with precast slab)
T es b Material & Fabrications
res resse recas re ens one
(most likely with precast concrete slab)
T es b Material & Fabrications
Prestressed Segmental Bridge
-
T es of Brid e b Structure
Arch
Beam
Cantilever
Cable-Stayed
Others
8/2/2019 40609 Types (1)
8/27
T es: Arch Brid e
Forces Along the Arch
Reaction ForcesReaction Forces
T es: Arch Brid e
Semi-circle (has vertical reaction
orce on y
Flat arch (has vertical and
Tied arch (tie resists tension
force)
T es: Arch Brid e
Hinge changes the degree of
hingless indeterminatcy in the structure
2 hinged
keystone
tie
voussoir
T es: Arch Brid e
Hinge Detail at the top of an arch bridge
8/2/2019 40609 Types (1)
9/27
T es: Arch Brid e
Ponte dei Salti Bridge
(circa 1st century AD)
Switzerland
Masonry Arch
The arch construction was
invented during the Romanem ire
Materials
Masonry
Concrete (Reinforced/ Prestressed)
Steel
T es: Masonr Arch Brid e
, ,
T es: Masonr Arch Brid e T es: Masonr Arch Brid e
8/2/2019 40609 Types (1)
10/27
T es: Masonr Arch Brid e T es: Concrete Arch Brid e
Bixby Bridge (1932)
California, USA
97.5 m s an.
Concrete arch
T es: Concrete Arch Brid e
Enz Bridge (1961)
Mlacker, Germany46 m span
Concrete arch
T es: Prestressed Concrete Arch
Natchez Trace Parkway Bridge (1994)
Tennessee, USA
502 m span
8/2/2019 40609 Types (1)
11/27
T es: Steel Arch Brid e
Sydney Harbor Bridge (1938)
Sydney, Australia
parabolic arch
503 m span
T es: Steel Arch Brid e
Construction of S dne Harbor Brid e
T es: Beam/Girder Brid es
Vertical Loads from Traffic
ROADWAY DECK The most basic type of
bridge
Typically consists of a
beam simply supported
PIER PIER
and can be made
continuous later
Typically inexpensive to
build
T es: Beam/Girder Brid es
Common Materials
Timber Truss
RC Beam
Steel Plate Girder/ Box Girder
Steel Truss Girder Prestressed Concrete Girders
I-Beam, U-Beam, T-Beam
8/2/2019 40609 Types (1)
12/27
T es: Beam/Girder Brid es
simple
cantilever
continuous
Currently, most of the beam bridges are precast (in case of RC and PC)
or prefabricated
- -
Some are made continuous on site
T es: Beam/Girder Brid es
Mountain Creek Bridge (1880)
Canada
Timber
T es: Beam/Girder Brid es
hot-rolled box plate girder
Steel sections may be hot-rolled shapes (for short-span bridge), Box
section (medium span), or Plate Girder (medium span)
T es: Beam/Girder Brid es
Steel Box
Girder
Bridge
8/2/2019 40609 Types (1)
13/27
T es: Beam/Girder Brid es
Upper: Steel Plate Girder Bridge
Lower: Prestressed Concrete I-Girder Bridge
T es: Beam/Girder Brid es
Steel Plate Girder
T es: Beam/Girder Brid es
Steel Plate Girder
ont nuous
T es: Beam/Girder Brid es
6'9" Prestressed Concrete
8"
recast an retens one
sections are usually of I-
shape
54"
28 o 0.5" strands
13@2" =26"
6@2" =12"
Typical Cross-Section of
Pretensioned AASHTOAASHTO Type IV Girder. Type IV girder
8/2/2019 40609 Types (1)
14/27
T es: Beam/Girder Brid es
Precast Pretensioned Prestressed Concrete Bridge
Simply-Supported Beam
T es: Beam/Girder Brid es
Post-Tensioned Prestressed Concrete are often found in the form of
segmenta y precast mem ers
T es: Beam/Girder Brid es T es: Beam/Girder Brid es
Segmental construction may be
constructe n ways
Cantilever Construction
construct from the pier equally
on both sides
Span-by-Span Construction n s one span a a me
Span-by-Span
Cantilever
8/2/2019 40609 Types (1)
15/27
T es: Beam/Girder Brid es
Some types of truss bridges can also be considered as a beam bridge
w en oo e g o a y
T es: Beam/Girder Brid es
T es: Beam/Girder Brid es
Steel Truss can be of beam type, arch type, or cantilever type
T es: Beam/Girder Brid es
Components of Truss
8/2/2019 40609 Types (1)
16/27
T es: Cantilever Brid es
In a cantilever bridge, the roadway is constructed out from the pier in two
rect ons at t e same t me so t at t e we g t on ot s es counter a ance
each other
T es: Cantilever Brid es
T es: Cantilever Brid es
Steel Truss Cantilever
Prestressed Concrete Segmental Cantilever Beam
350'
150'
1700'
Firth of Forth Bridge (1890), Scotland
521m span
T es: Steel Truss Cantilever Brid e
Firth of Forth Bridge (1890)
Scotland
521m span
8/2/2019 40609 Types (1)
17/27
T es: Steel Truss Cantilever Brid e T es: Cantilever Brid es
Prestressed Concrete Segmental Cantilever Beam
Columbia River Bridge
USA1950 ft span
T es: Cable-Sta ed Brid eTOWER/ PYLON TOWER/ PYLON
Vertical Loads from Traffic
ROADWAY DECK
PIER PIER
Reaction Force Reaction Force
T es: Cable-Sta ed Brid e
Cable-stayed bridge uses the prestressing principles but the prestressing
All the forces are transferred from the deck through the cables to thepylon
Roadway deck can be:
(Prestressed) Concrete Box Deck
Steel Box Deck
8/2/2019 40609 Types (1)
18/27
8/2/2019 40609 Types (1)
19/27
T es: Cable-Sta ed Brid e T es: Cable-Sta ed Brid e
Construction sequence
Construct Pylons
T es: Cable-Sta ed Brid e
Erect the deck away from the pylon in both of the pylons.
T es: Cable-Sta ed Brid e
Join the cable-stayed sections with the back piers (back piers helps resist tension forces)
T C bl S d B id T C bl S d B id
8/2/2019 40609 Types (1)
20/27
T es: Cable-Sta ed Brid e
The concrete roadway deck is laid as the deck structure is erected
T es: Cable-Sta ed Brid e
Finally, join the two cantilevers at the midspan
T es: Sus ension Brid e
Suspension bridge needs to have very strong main cables
Cables are anchored at the abutment abutment has to be massive
TOWER/ PYLONTOWER/ PYLON
Vertical Loads from Traffic
ROADWAY DECK
PIER PIER
ABUTMENTABUTMENT
T es: Sus ension Brid e
Forces in Main Cable
Reaction Forces
Reaction Force Reaction Force
T S i B id T es: Sus ension Brid e
8/2/2019 40609 Types (1)
21/27
T es: Sus ension Brid e
Anchor of a suspension bridge
T es: Sus ension Brid e
London Tower Bridge (1894)
London, UK 3-Hinged Suspension Bridge
T es: Sus ension Brid e
Mackinac Bridge (1957)
c gan,
1158 m span
Tacoma Narrows Bridge (1940)
Washington, USA
t span
T es: Sus ension Brid e
Akashi Kaik o Brid e 1998
Japan
1991m central span
T es: Sus ension Brid e T es: Sus ension Brid e
8/2/2019 40609 Types (1)
22/27
T es: Sus ension Brid e
Millennium
Footbridge
(2002)
London, UK
144m span
T es: Sus ension Brid e
T es: Sus ension Brid e T es: Others
Pontoon (Floating) Bridge
T es: Others
T es: Others
8/2/2019 40609 Types (1)
23/27
T es: Others
rotate to allow shipsto go under
Gateshead Millennium Brid e 2000
Gateshead, UK
126m span
T es: Others
Charin Cross Brid e middle - truss and Golden ubilee
Bridges (outer cable-stayed).
Which t e should I use?
Consider the followings:
Span length
Bridge length
Beam spacing
Material available
te con t ons oun at ons, e g t, space constra nts
Speed of construction
Technology/ Equipment available
Cost
S an Len th
steel rib arch
concrete arch
steel truss arch
cable-stayed steel
steel truss
Types
Ty p es m i n m a x
slab 0 12
concrete girder 10 220
steel irder
cable-stayed concrete
s ee g r er
cable-stayed concrete 90 250
cable-stayed steel 90 350
steel truss 90 550
concrete girder
concrete arch 90 300
steel truss arch 250 500
steel rib arch 120 370
steel suspension 300 2000
0 200 400 600 800 1000 1200 1400 1600 1800 2000
s a
S an Len th Cost vs S an Len th
8/2/2019 40609 Types (1)
24/27
S an Len th Cost vs. S an Len th
The span length may be influenced by the cost of superstructure
cost meter an su structure cost p er
If the substructure cost is about 25% of total cost shorter span is more
-
If the substructure cost is about 50% of total cost longer spans are
more economical
Cost vs. S an Len th
Substructure here is expensive
compared with the
If the water is shallow,
substructure is inexpensive
compared with the
superstructure
Access for Maintenance
Total Cost = Initial Cost + Maintenance Cost
Bridge should be made easy to inspect and maintain
Maintenance cost ma overn the selection of brid e
Steel bridge needs a lot of maintenance in coastal regions
Concrete bridge usually require the least maintenance
Beam S acin
Materials
8/2/2019 40609 Types (1)
25/27
Beam S acin
Beam spacing determine the
Large Spacing
Fewer girder (faster to erect)
Deeper and heavier girder (can itbe transported?)
Thicker slab
Smaller Spacing
More girder
Smaller girder
beams to inspect)
Thinner slab
Materials
Steel
Concrete
Cast-in-place
Precast
Material choice depends on the cost of material at the bridge
site
Shi in cost from fabricators
S eed of construction
In urban areas, the construction of bridge may disrupt traffic
Prefabricated/ Precast member are the only choice
Substructure construction may disrupt traffic more than the
superstructure erection may consider longer spans
Site Re uirement
Is the bridge straight or
curved
Precast I-Girder cannot be
curved
Segmental prestressed can have
Cast-in-place
pieces to site
Segmental pieces may
be easier to ship ins s pp ng c anne requ re
Is the temporary falsework
narrow urban streets
requ re an t e one w tthe site conditions?
Site Re uirement Site Re uirement
8/2/2019 40609 Types (1)
26/27
Site Re uirement
Requirement for shipping channel leads to long span bridge
Site Re uirement
In the Millau Aqueduct, the superstructure was completed inland and pushed into the span
Site Re uirement Aesthetics
An ugly bridge, however safe, serviceable, and inexpensive, is
not a good bridge
Long span bridge over a river can be a landmark; thus,
aesthetics should be an important factor
Bridge should blend with the environment Smooth transition between members
Bridge should have an appearance of adequate strength
Aesthetics Aesthetics
8/2/2019 40609 Types (1)
27/27
Determinant of bridges appearance (in order of importance)
Vertical and Horizontal geometry relative to surrounding topography
and other structures
Superstructure type: arch, girder, etc
Pier placement
utment p acement
Superstructure shape, parapet and railing
Abutment shape
, ,
Signing, Lighting, Lanscaping
Aesthetics Aesthetics