Skip to main content

CIVIL ENGINEERING==>>TYPES AND WORKING OF BRIDGE'S


How do bridge's work????


Although there are many types of bridges most bridges work by balancing compression and tension. Place a flexible object like an eraser, sponge, or small piece of bread between your thumb and index finger. Press your fingers together. One side of the object will bend inwards and shorten while the other will bend outwards and lengthen. The shorter side has been compressed, while the other side is under tension. Bridge
components experience these tension and compression stresses



ARCH BRIDGE ==>>
Arch bridge are structures in which each span forms an arch. The arch bridge is one of the oldest types of bridges. Early arch bridges were made from stone. The spans range up to about 1700 ft.


GIRDER BRIDGES ==>>

Girder bridges are made of beams called girders. The ends of the beams or girders rest on piers or abutments. The span length of girder bridges ranges up to about 1000 ft.

TRUSS BRIDGE==>>

Truss bridges are supported by frameworks called trusses. Trusses are beams arranged to form triangles.

CANTILEVER BRIDGE==>>

Cantilever bridges consist of two independent beams, cantilevers, that extend from opposite banks of a waterway. Cantilever bridges have spans as long at 1800 ft.

CABLE STAYED BRIDGE==>>

Cable-stayed bridges have roadways that hang from cables. The cables are connected directly to towers.

MOVEABLE BRIDGE==>>

Moveable bridges have roadway that is moved to provide enough clearance for boats or large ships to pass. An example of a moveable bridge is a drawbridge that tilts the roadway upward.

SUSPENSION BRIDGES==>>

Suspension bridges may be the most impressive type of bridge with their long main span and beauty. These bridges have a roadway that hangs from steel cables supported by two high towers. The difference between suspension bridges and cable-stayed bridges is that suspension bridge cables are not directly connected to the towers. The cables of a suspension bridge are not connected to the bridge - the cables pass through a hole in the top of the towers.


A suspension bridge has at least two main cables. These cables extend from one end of the bridge to the other. Suspender cables hang from these main cables. The other end of the suspender attaches to the roadway.


Suspension bridges have the longest spans in the world and are used to cross great distances. These types of bridges are used to cross deep water channels, cannons or gorges, where construction of supporting piers can be difficult. The towers can be placed far apart eliminating the need for multiple towers and piers. Some suspension bridges have a main span longer then 4000 ft. The longest suspension bridge in the world is in Japan (the Akashi- Kaikyo Bridge) and has a span over a mile long. The largest bridges have cables several feet wide which weigh thousands of pounds per foot. For that reason the cables are spun in place.
Labels:

Comments

Post a Comment

Popular posts from this blog

civil engineering-->>Determinacy, Indeterminacy and Stability of Frames

Determinacy, Indeterminacy and Stability of Frames : Structural engineers must be able to apply judgment rather than stated rules. The most important aspect of structural design is not the ability to apply formulas or manipulate mathematics. The most important skill for the structural engineer is to be able to stand back, look at a drawing or sketch and determine whether a structure is stable, and if it is stable, to be able to determine how it will carry the applied loads. For a very complicated structure this might be more difficult and a computer can provide some help, but ultimately it is the skill and concern of a good structural engineer which produces good structural designs which have integrity. Another important closely related skill is the ability to determine whether, and to what degree, a structure is statically indeterminate. There really aren’t  many rules and rules may be difficult to apply in any case. For this reason, we need experience. A skilled structural...
1 comment
Read more

civil engineering-->>Asphalt Binder Modifiers

Asphalt Binder Modifiers Some asphalt cements require modification in order to meet specifications.  Asphalt cement modification has been practiced for over 50 years but has received added attention in the past decade or so.  The added attention can be attributed to the following factors (Roberts et al., 1996): Increased demand on HMA pavements .  Traffic volume, loads and tire pressures have increased substantially in recent years, which can cause increased rutting and cracking.  Many modifiers can improve the asphalt binder's stiffness at normal service temperatures to increase  rut  resistance, while decreasing its stiffness at low temperatures to improve its resistance tothermal cracking. Superpave asphalt binder specifications .  Superpave asphalt binder specifications developed in the 1990s require asphalt binders to meet stiffness requirements at both high and low temperatures.  In regions with extreme climatic conditi...
1 comment
Read more

civil engineering-->>Properties of Bitumen

Properties of Bitumen Adhesion :  Bitumen has the ability to adhere to a solid surface in a fluid state depending on the nature of the surface. The presence of water on the surface will prevent adhesion. Resistance to Water :  Bitumen is water resistant. Under some conditions water may be absorbed by minute quantities of inorganic salts in the bitumen or filler in it. Hardness:  To measure the hardness of bitumen, the penetration test is conducted, which measures the depth of penetration in tenths of mm. of a weighted needle in bitumen after a given time, at a known temperature. Commonly a weight of 100 gm is applied for 5 sec at a temperature of 77 °F. The penetration is a measure of hardness. Typical results are 10 for hard coating asphalt, 15 to 40 for roofing asphalt and up to 100 or more for water proofing bitumen. Viscosity and Flow :  The viscous or flow properties of bitumen are of importance both at high temperature during processing ...
Post a Comment
Read more