LRFD Curved Girder Bridge Design
LRFD Curved Girder Bridge Design
(OP)
I am about to use DESCUS I to design a curved girder bridge with 2005 LRFD spec. Is the program able to handle the new code? Thanks ahead for any input!
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LRFD Curved Girder Bridge Design
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RE: LRFD Curved Girder Bridge Design
Regards,

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RE: LRFD Curved Girder Bridge Design
RE: LRFD Curved Girder Bridge Design
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RE: LRFD Curved Girder Bridge Design
What did you do when specifying the DFs? Maybe I should just let the program handle it with S/11 over all the girders?
RE: LRFD Curved Girder Bridge Design
If this is your first LRFD bridge design project, it may be worth it to go ahead and do calculations for ALL of the beams on your bridge. LRFD is more calculation intensive than the standard specs. You will spend more time to get loads than you would have to calculate loads under the standard specs. But in the end you will have a good example set of calculations to refer to when you do your next LRFD bridge design. Once you have some experience you can begin to weed out some of the un-neccesary calculations.
Good Luck.
RE: LRFD Curved Girder Bridge Design
As to the lateral load distribution factor calculation, the policy in our office is to use lever rule for curved girders and neglect the AASHTO Tables in chapter 4. This is consistent with DESCUS user input method for card 0301. The confusion I had for a while is to whether to include multiple presence factor (LRFD) or load intensity reduction factor (Std. Spec). I ran Auto-DF yesterday and noticed the porgram gives me options about whether to include it or not. For average girder spacing, the effect on DF calcs is just one (exterior girder) or two (interior girder) trucks. To include more trucks or lanes will only reduce the effect due to the less than 1.0 multiple presence factor. Things are a little easy with ASD design since this factor is 1.0 for both one and two lane loaded conditions. In LRFD, this is 1.2 for signle lane and 1.0 for two lane loaded condition. So I probably need to be very careful when I start to calculate the DFs in LRFD to maximize the force effect.
Well, I am gonna stop here. I guess you guys probably have figured that out long time ago. I don't know if I made things clearer or not. I just finally got to point a minute ago
Keep letting me know if you have any thoughts/ideas .... Thanks ahead!
RE: LRFD Curved Girder Bridge Design
RE: LRFD Curved Girder Bridge Design