How many US DOT are currently using AASHTO LRFD for bridge design?

Question

How many US DOT are currently using AASHTO LRFD for bridge design?

yjung (Civil/Environmental)

(OP)

29 Aug 03 14:14

I am wondering how many US DOT are currently using AASHTO LRFD code for their bridges.

Arizona = ASD
Washington = LRFD

I am not sure about other states. Can anyone tell me about it?

rowe (Structural) · Answer 1 · 2003-08-29 15:29:03

RE: How many US DOT are currently using AASHTO LRFD for bridge design?

rowe (Structural) 29 Aug 03 15:29

SCDOT = LRFD

Qshake (Structural) · Answer 2 · 2003-08-31 11:54:48

Kansas DOT - LRFD
IDOT - has been on the verge for years. Just never made it over the top.
MoDOT - LFD/ASD
PennDOT - LRFD

rowe (Structural) · Answer 3 · 2003-09-03 09:51:19

It's my understanding that AASHTO's current plan is to not issue any more editions of LFD (although interims are to continue until 2007 - I think). Therefore, it seems that most states will soon have to adopt LRFD or maintain their own LFD standard.

koodi (Civil/Environmental) · Answer 4 · 2003-09-04 15:10:15

Rowe, what is this about LFD and LRFD, I thought they were the same thing. Load Factor Design = Load Resistance Factor Design?

Qshake (Structural) · Answer 5 · 2003-09-05 16:05:53

KOODI,

The concepts of load factors are similar, but with LRFD you also have resistance factors to apply for material behavior.

Definitely not the same thing.

dbags (Structural) · Answer 6 · 2003-09-05 17:00:05

RE: How many US DOT are currently using AASHTO LRFD for bridge design?

dbags (Structural) 5 Sep 03 17:00

ConnDOT = LRFD

rowe (Structural) · Answer 7 · 2003-09-08 08:34:54

To All,

Qshake is right. The concepts are similar. BUT, The AASHTO LRFD Guidelines are VASTLY different than LFD. I would suggest to all who are planning to continue in bridge design to invest in the latest LRFD manual. It's not an easy leap; it will require alot of reading beyond the "articles". Fortunately, the LFRD is written similar to the ACI in that there is a running commentary on the same page as the article (I found this very helpful).

The LFD code was written similar to ACI's (1.4DL + 1.7LL, etc.). The LRFD codes have incorporated specific bridge studies to incorporate bridge statistics (not buildings) with alot of consideration to areas not specifically addressed by the LFD (e.g. skewed bridges).

bridgebuster (Civil) · Answer 8 · 2003-09-10 18:04:26

NJDOT, FDoT, and WVDOT = LRFD

NYSDOT is heading towards LRFD

TexasAggieCE (Structural) · Answer 9 · 2003-09-26 10:59:52

TxDot = LFD/ASD - but looks like maybe a very (could be really slow) move to LRFD.

On a side note - I am working at getting my masters degree in structural engineering at night at the University of Houston. I took a bridge design course last spring and we were taught the LRFD code. I do believe that TxDot is beginning to look at what it might take to switch, but I could be wrong. TxDot has issued some standard bridge designs (for just a CIP slab bridge) using the LRFD code.

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How many US DOT are currently using AASHTO LRFD for bridge design?