Types of Bridge(Concept)

Data Collected by:

Kushal Patel

DEFINITION: Bridge• A structure made for carrying road traffic or other moving load

over a obstruction such as river, road or railway is said to be as bridge.

Uses of Bridges

• Walkways• Highways/Roads• Railways• Pipelines• Connecting lands• Crossing rivers and

canyons

Site Selection for Bridge1. A straight reach of the river.

2. Steady river flow without cross currents:

3. A narrow channel with firm banks

4. Suitable high banks above high flood level on each side.

Site Selection for Bridge

5. Rock or other hard in erodible strata close to the river bed level.

6. Economical approaches which should not be very high or long or liable to flank attacks of the river during floods, the approaches Should be free from obstacles such as hills, frequent drainage crossings, scared places, graveyards or built up areas or troublesome land acquisition

Site Selection for Bridge7. Absence of sharp curves in the approaches.

8. Absence of expensive river training works.

9. Avoidance of excessive underwater construction.

ECONOMIC SPAN• THE SPAN OF THE BRIDGE WHICH REDUCES OVERALL COST OF

BRIDGE TO BE MINIMUM.• THE OVER ALL COST OF BRIDGE DEPENDS ON FOLLOWING FACTOR:• COST OF MATERIAL• AVALIABLITY OF SKILLED LABOUR• SPAN LENGTH• CLIMATIC CONDITION

AFFLUX• WHEN BRIDGE IS CONSTRUCTED THE STRUCTURES SUCH AS

ABUTMENT, WING WALL, PIERS CAUSE REDUCTION IN NATURAL WATER WAY AREA. THIS CONTRACTION IS SAID TO BE AS AFFLUX.

FREEBOARD• THE VERTICAL DISTANCE BETWEEN DESIGNED HFL AND THE MAIN

CARRYING ELEMENT

Types of Bridges

• Arch

• Truss

• Cantilever

• Cable-Stayed

• Suspension

What makes a bridge stay up?

• Forces• Compression – a pushing

or squeezing force• Tension – a pulling or

stretching force

Arch Bridges

• Keystone – the wedge-shaped stone of an arch that locks its parts together• Abutments – the

structures that support the ends of the bridge

Arch Bridges

• Works by

Compression

Arch Bridges

Cold Spring Arch Bridge, Santa Barbara, CA

Marsh Rainbow Arch, Riverton, KS

Pont du Gard, Nimes, France

Cable-Stayed Bridges• Piers – the vertical supporting structures• Cables – thick steel ropes from which the decking is

suspended• Decking – the supported roadway on a bridge

Cable-Stayed Bridges• Works by Tension AND Compression

Cable-Stayed Bridges

Zakim Bridge, Boston, MA

Sunshine Skyway Bridge, Tampa, FL

Sundial Bridge, Redding, CA

Suspension Bridges• Similar to Cable-Stayed• Different construction method

Suspension Bridges• Works by Tension and Compression

Suspension Bridges

Golden Gate Bridge, San Francisco, CA

Brooklyn Bridge, Brooklyn, NY

Verrazano-Narrows Bridge, New York, NY

Truss

Southern Pacific Railroad Bridge, Tempe, AZ

Questions?