BRIDGE CONSTRUCTION

mowafi3m · 06-06-2011, 08:38 AM

BRIDGE CONSTRUCTION

INTRODUCTION
Bridges play an important role in linking different parts of highway networks, and therefore have a great impact on the capacities of such networks. Bridges are massive structures that require large amounts of materials, skilled labor, and heavy machinery for their construction. Therefore, the decision regarding the most convenient construction system should be based on careful evaluation of all applicable alternatives, and using evaluation criteria appropriate for each project.

The construction of bridges had started very long time ago. However, the bridge construction technologies have evolved in the 20th century, and were fueled by the Industrial Revolution. At the turn of the century, steel bridges were riveted together, not bolted; concrete bridges were cast in place, not precast; and large bridge members were built from lacing bars and smaller sections, not rolled in one piece. Construction techniques such as post-tensioning, slurry walls, soil freezing, and shield tunneling had not yet been conceived. Bridge construction is changing as the new millennium begins. New construction techniques and new materials are emerging. There are also new issues facing the bridge construction technologies relative to the research needs associated with the new techniques and materials introduced.

Over many decades, various construction systems for bridges have been developed and successfully used. Most of these systems, with advances and modifications, are still in use until today. The objective of this material is to review the state of the art in the area of bridge construction. This involves the latest construction systems and future trends for this type of structures.

For each construction system, a brief description is outlined that includes: system concept, main system components, construction sequence, system advantages, and system disadvantages and limitations. In addition, the bridge construction in Egypt is discussed in view of the applicability of various construction systems under the Egyptian construction environment. This includes the potential of using the promising systems yet to be applied in Egypt.

Bridges can be classified according to their purpose into highway bridges, elevated roads, railway bridges, and foot bridges. This material is limited to highway bridges and elevated roads since their work volume constitutes more than 90% of the total volume of bridge works in Egypt. Only the construction systems for bridge superstructures are included.

Further, bridges can be classified according to their material of construction into timber, masonry, steel, reinforced concrete, and prestressed concrete. The material is limited to prestressed concrete bridges since most recent developments in the bridge construction systems are found in this category.

Code:
***************************************

Content of this section is hidden, You must be registered and activate your account to see this content. See this link to read how you can remove this limitation:

http://forum.civilea.com/thread-27464.html

***************************************

Made By CivilEA Post-Generator ver 2.1