40609 Types (1)

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


Superstructure Roadway Deck

Abutment Abutment

uperstructureRoadway Deck

Pier

Abutment

Substructure


Bearing

8/2/2019 40609 Types (1)

2/27


Pin Joint

Bearing

ap eam


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?


Leonardo Da Vinci Bridge (2001)

Norway

40 m Span

Glue-laminated Timber Bridge

8/2/2019 40609 Types (1)

7/27


Steel

Prefabricated

(probably with precast slab)


res resse recas re ens one

(most likely with precast concrete slab)


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


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


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


Mountain Creek Bridge (1880)

Canada

Timber


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)


Steel Box

Girder

Bridge

8/2/2019 40609 Types (1)

13/27


Upper: Steel Plate Girder Bridge

Lower: Prestressed Concrete I-Girder Bridge


Steel Plate Girder


Steel Plate Girder

ont nuous


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


Precast Pretensioned Prestressed Concrete Bridge

Simply-Supported Beam


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


Some types of truss bridges can also be considered as a beam bridge

w en oo e g o a y



Steel Truss can be of beam type, arch type, or cantilever type


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



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


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


Erect the deck away from the pylon in both of the pylons.


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


The concrete roadway deck is laid as the deck structure is erected


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


ROADWAY DECK

PIER PIER

ABUTMENTABUTMENT


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


Anchor of a suspension bridge


London Tower Bridge (1894)

London, UK 3-Hinged Suspension Bridge


Mackinac Bridge (1957)

c gan,

1158 m span

Tacoma Narrows Bridge (1940)

Washington, USA

t span


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


Millennium

Footbridge

(2002)

London, UK

144m span


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

40609 Types (1)

Documents

Transcript of 40609 Types (1)