The H-steel girder bridge has the maximum girder height up to 912mm and is inexpensive in terms of the unit weight because of mass-produced and besides, the transportation and on-site building are easily conducted allowing an applicable span length up to around 25 meters. The I-girder is easy to fabricate besides being the most light-weighted in steel mebers, and is economical. The box grider bridge is provided with large torsional rigidity as well as bending rigidity and is suited for long span bridges and curved bridges. It is more complex in design and building process compared with the I-girder structure and lacks a lot in the freedom of cross-sectional variation, therefore, the cost of construction will be relatively high if applied to a bridge with short spans. A truss is structure consisting alone by axial tensile members and axial compression members with a view to imparting a resisting property as a whole. This structure enables a bridge to raise the height of main truss without drastically increasing the web members as in the case of the plate girder bridge. Consequently, the struture allows to construct a bridge with long spans having greater load durability with relatively small quantity of steel by virtue of the combined use of small and light-weight members. The arch bridge is the oldest and was known to prehistoric people. It has many styles but largely divided into three categories: Arch Bridge: the arch ribs are designed based on bending shearing and axial forices. Langer Bridge: the arch ribs are designed based on axial force alone. Stiffening girders are designed based on bending, shearing and axial forces. Lohse Girder Birdge: the arch ribs and stiffening girders are designed based on bending, shearing and axial forces.

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