How to calculate parapet loading for bridge when equal distribution not possible?
How to calculate parapet loading for bridge when equal distribution not possible?
(OP)
I am reviewing the parapet loading requirement for a steel girder concrete deck bridge and had a question regarding load distribution.
Reviewing the uniform application of dead load requirement in AASHTO (Section 4.6.2.2.1 and Section 4.6.1.2.4b), the parapet loading will not be equally distributed among all the girders since the bearing lines of the curved girders that I am designing are skewed more than 10 degrees from radial.
AASHTO only says to use engineering judgement if the criteria for equal distribution is not satisfied.
Has anyone come across this situation before? How much additional parapet loading should be added to the exterior girder, if any?
Is the lever rule a way to designate loading for such a case?
Reviewing the uniform application of dead load requirement in AASHTO (Section 4.6.2.2.1 and Section 4.6.1.2.4b), the parapet loading will not be equally distributed among all the girders since the bearing lines of the curved girders that I am designing are skewed more than 10 degrees from radial.
AASHTO only says to use engineering judgement if the criteria for equal distribution is not satisfied.
Has anyone come across this situation before? How much additional parapet loading should be added to the exterior girder, if any?
Is the lever rule a way to designate loading for such a case?
RE: How to calculate parapet loading for bridge when equal distribution not possible?
You need to follow 4.6.3.
RE: How to calculate parapet loading for bridge when equal distribution not possible?
RE: How to calculate parapet loading for bridge when equal distribution not possible?
Section 4.6.4 gives options for refined methods. You can do a grillage analysis but you would need to somehow approximate the forces in cross frames/diaphragms, which are primary members in a curved bridge.
RE: How to calculate parapet loading for bridge when equal distribution not possible?