Box Girder Bridge for Overpass And Expressway

Box Girder Bridge for Overpass And Expressway
Bridge, as an increasingly important transportation facility, gradually
developed from the original period, from naturally fallen trees, naturally
formed stone beams or arches, to later man-made wooden bridges, stone bridges,
materials are increasingly advanced. Especially steel bridge, although only
more than 200 years of development history, but because of its own
characteristics

Introduction
 
S , teel beam Bridges include steel beam bridge and steel truss bridges of simply
supported or continuous system. Steel girder bridges are generally processed
in factories and constructed on site. There are many construction methods,
including the whole hole hoisting method, bracket assembling method, cable
hoisting method, turning method, pushing method, dragging method and cantilever
assembling method.
 
Steel box girder, also called steel plate box girder, is a common structural
form of long span Bridges. It is generally used on Bridges with large spans.
Steel box girder bridge is more and more frequently used in highway Bridges,
especially in urban overpasses and cross-line Bridges. There are mainly single
box girder bridge, double box girder bridge and multi-box girder bridge. The
steel box girder is generally made up of the top plate, bottom plate, web,
diaphragm plate, mediastinum plate and stiffening rib, etc., which are
connected by all-welding method.

Advantages of steel bridge
 
1) Great spanning ability
Because of the high strength of steel, and then under the same bearing capacity
conditions, compared with the reinforced concrete bridge, steel bridge
component section is smaller, so the steel bridge weight is light,
more suitable for the construction of large-span bridge.
 
2) Suitable for industrial manufacturing. 
Steel bridge components are generally manufactured in specialized factories by
professional equipment, not limited by the season, processing and manufacturing
speed, high precision, quality is easy to control.
 
3) Easy to transport
Due to the light weight of steel bridge components, especially in the
mountainous areas with inconvenient traffic, steel
bridge is more convenient for automobile transportation
 
4) Erection fast
Steel bridge members are easy to cantilever construction method assembly,
complete sets of equipment available, assembly process mature.
 
5)Steel bridge members are easy to repair and replace

The steel used in the main structure of steel bridge is mainly carbon steel and
low alloy steel. Steel plates are the most commonly used in modern steel
Bridges. Materials for steel bridge will go through many machining processes
and welding processes, then make the bridge to be able to withstand a large
static, dynamic load and impact load. Therefore, the steel materials used for
Bridges should not only meet the requirements of manufacturing process, but
also meet the requirements of use.

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