04-05-2012, 02:53 PM
Design of Steel Structures
4_load_&_load_combination.pdf (Size: 210.89 KB / Downloads: 345)
Loads and Load combinations
Loads on bridges
The following are the various loads to be considered for the purpose of
computing stresses, wherever they are applicable.
· Dead load
· Live load
· Impact load
· Longitudinal force
· Thermal force
· Wind load
Dead load – The dead load is the weight of the structure and any permanent
load fixed thereon. The dead load is initially assumed and checked after design is
completed.
Live load – Bridge design standards specify the design loads, which are
meant to reflect the worst loading that can be caused on the bridge by traffic,
permitted and expected to pass over it. In India, the Railway Board specifies the
standard design loadings for railway bridges in bridge rules. For the highway
bridges,
Highway bridges: In India, highway bridges are designed in accordance with
IRC bridge code. IRC: 6 - 1966 – Section II gives the specifications for the
various loads and stresses to be considered in bridge design. There are three
types of standard loadings for which the bridges are designed namely, IRC class
AA loading, IRC class A loading and IRC class B loading.