CE 414 Introduction to Bridges Engineering

Asst Prof Mansoor Khalid

What is a BRIDGE? •Bridge is a structure which covers a gap

•Generally bridges carry a road or railway across a natural or artificial obstacle such as, a river, canal or another railway or another road

•Bridge is a structure corresponding to the heaviest responsibility in carrying a free flow of transport and is the most significant component of a transportation system in case of communication over spacings/gaps for whatever reason such as aquatic obstacles, valleys and gorges etc.

Bridge is the KEY ELEMENT in a Transportation System

History

• Primitive Peoples: – Logs – Slabs of Rocks – Intertwined Vines or Ropes

• Roman Empire—First Great Bridge Builders – Timber Truss Bridges – Masonry Arch Bridges

• Europeans – Followed HRE Until Iron and Steel Use

• Nineteenth Century— – Modern Long Bridges – Moveable Bridges

Rock Bridges

Wadi Rum Rock Bridge

Rope Bridges

Log Bridges

LOG BRIDGE

Members of a Denver and Salt Lake Railroad Company (D&SL) survey crew pose on a log bridge over the Colorado River in Gore Canyon (Grand County), Colorado.

View of a settlement in (probably) Utah; shows a log bridge, a stream, and houses. People sit on a porch; a United States flag waves from a pole.

U.S. Army soldiers from the Ohio Engineers, building a small log bridge over a ditch, at Fort Sheridan, Illinois

LOG BRIDGE View of hot springs site enclosed by stone and wooden frame buildings, Hot Sulphur Springs, CO

Covered Bridges

COVERED BRIDGE

• Bridges. Old covered bridge, Jackson River, Va.

Structure of covered bridge. Wallingford, Vermont

Covered Bridge, Glen Canyon, Santa Cruz

County, CA

CONSTRUCTION

• Must carry own weight and weight of traffic – Must withstand force of high winds

– Must consider effects of contraction and/or

– Expansion due to temperature changes

– Most common materials • Wood—temporary

• Steel—for long, strong spans

• Reinforced concrete—attractive designs but difficult to work with on large bridges

• Prestressed concrete—stronger than reinforced, cheaper than steel

TYPES OF BRIDGES

•Fixed

•Moveable

•Other

Beam or Girder Bridges

FIXED

• Beam or Girder

– Two parallel beams w/ flooring supported by piers

– Span can be supported by trestle

– Used for hwy over/underpasses or small stream crossings

– Example—Covered Bridge

Cars on a suspension bridge over a river, possibly in Colorado.

enz_bridge.jpg

Millennium Bridge, London

ostruz.jpg www.prevodi-vertalingen.com/.../ ostruz.html

Truss Bridges

FIXED

• Truss

– Beam bridge strengthed by trusses (structural spts joined to form triangles with tie rods)

– Lighter than ordinary beam sections of equal length

– Useful for longer bridges

Timber Truss Bridge

Continuous Truss Bridges

View west of an iron truss bridge crossing the Colorado River on the Denver and Rio Grande Railroad Montrose line at Grand Junction, Colorado; people and horses are on a sand bar.

View of the bridge crossing the White River at Meeker, CO on the Mesa and Flag Creek road.

White Water Creek Bridge, Spanning White Water Creek, Bernard vicinity, Dubuque County, IA

Truss Bridge

View of a trestle bridge that crosses Arastra Gulch near Silverton (San Juan County), Colorado.

Jefferson Barracks Bridge Location: Mississippi River, Jefferson Barracks, Missouri

Simple Truss Bridges

FAI 24 Bridge Over the Ohio River Paducah, Kentucky

FAI 24 Bridge Over the Ohio River Paducah, Kentucky

www.modjeski.com/projects/ servproj/paducah.htm

gcdranet.homelinux.com/davehonan/ bridges/il.html Cairo

Ohio River ferry and railroad bridge, Metropolis, IL

Arch Bridges

FIXED

• Arch

– One or more arches

– Masonry, reinforced concrete or steel

– Roadway on toop of arches or suspended by cables

– Spans can be longer than beam or truss

Aquaduct

Old stone bridge at Bull Run Battlefield. Manassas, Virginia.

Stone bridge in Rock Creek Park.

Stone bridge, Elizabeth Park, Hartford, Ct..

Old Stone Bridge, Boonton, N.J..

Stone Bridge at Bowling Green, Gallatin vicinity, Sumner County, TN

Segovia, Spain

Franklin Park, Ellicott Bridge, Emerald Necklace, Boston, MA

Pont du Gard

Arch bridge, Bellows Falls, Vt..

Bayonne Bridge, Spanning Kill Van Kull between Bayonne & Staten Is, Bayonne, Hudson County, NJ

Kill van Kull Bridge

[Hell Gate Bridge (New York Connecting RailroadBridge), New York].

[Hell Gate Bridge (New York Connecting RailroadBridge), New York].

Steel Arch Bridge, Niagara.

700 A.D. Asia

100 B.C. Romans

Natural Bridges

Clapper Bridge

Tree trunk Stone

The Arch Natural Cement

Roman Arch Bridge

History of Bridge Development

Great Stone Bridge in China

Low Bridge Shallow Arch

1300 A.D. Renaissance

Strength of Materials

Mathematical Theories

Development of Metal

First Cast-Iron Bridge

Coalbrookdale, England

1800 A.D.

History of Bridge Development

Britannia Tubular Bridge

1850 A.D.

Wrought Iron

Truss Bridges

Mechanics of Design

Suspension Bridges

Use of Steel for the suspending cables

1900 A.D.

1920 A.D.

Prestressed Concrete

Steel

2000 A.D.