Bluetree,
If you are with a city or county official, have your State DOT review the load rating. By the description of the bridge, I assume it is an off-system bridge (bridge owned by county or city or some other local government).State DOT's are given the responsibility to make sure that...
TxDOT has done extensive research in the effects of lateral bracing and the items listed above in my previous posting is straight from their bridge load rating manual based on their current research. You still have to look at the structure and use your engineering judgment to what you feel...
No, it is not stated in AASHTO manual, When doing load ratings on existing bridges, some engineering judgment is used. TxDOT has a bridge load rating manual that allows the top flange to be fully braced under certain condition such as the timber deck planks covered with over 6" of base and...
Check to see if they used the proper section modulus for the Load Factor Method. The load factor design method requires the plastic modulus (Z) and not section modulus (S).http://www.eng-tips.com/viewthread.cfm?qid=284465#post
If you still need help, I will lay out all the steps for you. I have extensive structural and geotechnical background. Do you know what type soil do you have in your area? Clay? Sand? I won't be back until November 9, 2010. If you still need help by then, I will gladly help you in detail. I will...
There was some research done that if you had large dead loads on the top flange, the top flange would not rotate.The weight of the 8" slab provides frictional resistance to movement of the top flange. See report referenced in my previous posting. Looking at the numbers they gave you, I suspect...
Ran some quick load ratings but I did not know about your misc dead loads like rails, diaframs, and etc. You did not indicate if you have an asphalt overlay so my numbers will probably be smaller.http://www.eng-tips.com/viewthread.cfm?qid=284465&page=1#post
ASD IR H 28.0 & HS 27.1
OR H 42.9 & HS 40.1
LFD IR H 21.8 & HS 20.4
OR H 36.4 & HS 34.0
I did not know how old your bridge is. I assume fy=36ksi. If your bridge is between 1937 to 1963 then fy=33ksi.
If your bridge is between 1905 to 1936 then fy=30ksi.
In regards to bracing of the...
ASD IR H 28.0 & HS 27.1
OR H 42.9 & HS 40.1
LFD IR H 21.8 & HS 20.4
OR H 36.4 & HS 34.0
I did not know how old your bridge is. I assume fy=36ksi. If your bridge is between 1937 to 1963 then fy=33ksi.
If your bridge is between 1905 to 1936 then fy=30ksi.
In regards to bracing of the...
