Info on AASHTO Group Loadings

[apetr26542]

I am performing a load rating of an existing bascule bridge. We are using the 16th Ed. AASHTO. Table 3.22.1A Lists the load combinations for groups I to X. I am under the impression that each group applies to certain types of bridge structure but I can not verify what groups I should be using. Is it somewhere in this code? Does anyone Know what groups are used for what?

 

[ghghghgh]

I've always used the group case that produces the critical loading for the particular structure, however, commonsense dictates you exclude the group loadings that are irrelevant to a particular bridge, i.e. stream force on a grade seperation etc.
Unfortunately, there is no one group that will always govern for one type of structure, you have to check each pertinent group.

 

[bridgebuster]

Normally, a load rating only considers dead load of the structure and the the truck load. I'm assuming that you want to determine the maximum HS truck the structure can carry. The old AASHTO "Manual for the Maintenance Inspection of Bridges" shows the load rating procedure. You can also find it in the AASHTO "Manual for the Condition Evaluation of Bridges".

The Group Loads are mostly for substructure design.

 

[apetr26542]

Thanks for your reply'S!