Concrete Bridge Project Essays

765 Words 4 Pages
In the past, it is not much pedestrian traffic along the street because of the lower population. However, due to the population increasing in 1960-70s.The government considerate that the number of pedestrian traffic such as footbridge is so important, so the government have to increase the total number of all pedestrian traffic like footbridge. With the time changed, the safety and technical of bridge structure form has also changed and improved. Nowadays, almost footbridge in Hong Kong is made by concrete including prestressed concrete bridge.
This project will discuss about some basic structure analysis of prestressed concrete bridge and design a newly footbridge according the structure design manual for highway department.

First, there
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Most truss bridges have one set of truss on each side of the roadway. Typical Span Length of a truss bridge ranges from 40m - 500m
Warren Truss
The most common use of bridge truss is the Warren Truss.
A Warren truss can be identified by the presence of many equilateral or isosceles triangles formed by the web members which connect the top and bottom chords.
For smaller spans, no vertical members are lending the structure a simple look.

Unlike the beam, which without the tensile as well as compressive forces, a true arch is in a state of compression. That‘s mean it is strong in compression and weak in tension.
The arch profile is aesthetically pleasing and it provides a structure which eliminates tensile stresses in spanning an open space. This is useful because several of the available building materials such as stone, cast iron and concrete are strong in compression but are weak when tension.

Principles of prestressing:
Force transfer between the prestress tendon and the concrete achieves prestressing of the concrete member. Tendons are pulled and stretched and then anchored against the concrete, with the tension in the tendon being balanced by compression in the concrete. In this way an external compressive force is applied to the concrete and is used to counter the tensile stresses generated under the bending moments and shear forces present.
The prestress in a structure is influenced by either of the two

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