# Civil Exam:Bridge Questions



## ARLORD (Jan 10, 2009)

Are there many bridge questions on the Civil/Structural exam. I don't plan to buy AASHTO.

All I have is an old version of Tonias, 1995.

Just curious, for you bridge guys, what is the latest version of Tonias, if not 1995?


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## ramicoce (Jan 10, 2009)

ARLORD said:


> Are there many bridge questions on the Civil/Structural exam. I don't plan to buy AASHTO.All I have is an old version of Tonias, 1995.
> 
> Just curious, for you bridge guys, what is the latest version of Tonias, if not 1995?


When I took the civil/structural, the bridge questions weren't particularly intense. However, to get them right, you either had to really know your bridge stuff or have the code (or at the very least, the latest SERM). If you're golden in everything else, then maybe you can get through the test without the bridge questions... only you know if you're in that position. I went for every problem I could.

I don't know anything about Tonias' book, including whether or not its based on LRFD or Standard Spec. The book you're planning on taking as your reference is 14 years old, and 10 years behind the code referenced on the NCEES website. Plus LRFD, which is the code identified by NCEES, came out in it's first edition in 1994, and a lot has changed between then and the 3rd edition.


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## MonteBiker (Jan 12, 2009)

ARLORD said:


> Are there many bridge questions on the Civil/Structural exam. I don't plan to buy AASHTO.All I have is an old version of Tonias, 1995.
> 
> Just curious, for you bridge guys, what is the latest version of Tonias, if not 1995?


Does your firm have a copy of AASHTO that you could borrow for a few days? I took the one that I keep on my desk. There is a chance that you would not need it but there is always a chance that they are going to ask you a question just to see if you brought it (ie: what is the factor for X in situation Y) and it can only be answered with the correct code. If your firm doesn't have it, go to a few meetings of one of the local engineering societies and make some friends who might have books you can borrow. I ended up borrowing the green book from the coworker of a friend I cycle with and lucky I did. There was a preference question that was answered by just looking up the general topic. The guy only asked for a 6 pack of Old Milwaukee in return. After the book helped with the one question, I bought him two just as a nice thank you.

It is not hard to borrow a few books for the few days around the test. These just might be the references that PPI tells you to go to but it is best to have them if all of the sudden you have to look up a table that they do not have in CERM.


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## dastuff (Jan 12, 2009)

My theory was that I didn't want to spend the time learning the new material (seeing how we never use it in our firm).

So i just guessed on those questions. Although it sucks because from the sound of them they're easier than the rest, but my firm doesn't have the AASHTO and I wasn't about to fork over 250$ for it.

We'll see how I did in a few more weeks (CA is so slow...)


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## IlliniASU (Jan 12, 2009)

I would get a copy of the AASHTO LRFD 3rd edition, if at all possible. Borrow it from someone and spend a little bit of time getting to know it. You may end up getting an exam where there could be 5 bridge questions, and you'll be kicking yourself that you don't have it. The SERM will not be of much help because it is not updated to LRFD. At least, the third edition of SERM isn't. I'm not sure if there is a newer edition.


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## MonteBiker (Jan 12, 2009)

IlliniASU said:


> I would get a copy of the AASHTO LRFD 3rd edition, if at all possible. Borrow it from someone and spend a little bit of time getting to know it. You may end up getting an exam where there could be 5 bridge questions, and you'll be kicking yourself that you don't have it. The SERM will not be of much help because it is not updated to LRFD. At least, the third edition of SERM isn't. I'm not sure if there is a newer edition.


There is a 4th edition of SERM which covers the correct LRFD.


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## ARLORD (Jan 12, 2009)

I am a building guy, but I know a little bridge design theory from college.

What do you guys mean by AASHTO LRFD. Is that LRFD steel design or a LRFD method of bridge design?


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## MonteBiker (Jan 12, 2009)

ARLORD said:


> I am a building guy, but I know a little bridge design theory from college. What do you guys mean by AASHTO LRFD. Is that LRFD steel design or a LRFD method of bridge design?


We are talking about the approach to bridge design now being LRFD based (similar to the change to LRFD in steel design)... It has more or less replaced the older Standard Specifications for Bridge design. Your are now factoring your loads, just as you would do in steel design. The processes are pretty different than the previous WSD/LFD procedures. My suggestion would still be to have a copy of the correct manuals with you. You never know when they are going to ask you some question just to check and see if you have the correct materials with you. That would just be my $0.02.


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## IlliniASU (Jan 12, 2009)

I agree with Monte.

Best to have the code... it may be a simple look up like what load factor do you use... (example here, this was not on the test).

I've attached the LRFD vs the LFD load combination pages. You can kind of see where having the manual for a look up type question would help out. If I didn't have all of chapter 3 tabbed up, I would have scanned it all for you.


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## ARLORD (Jan 12, 2009)

OK bridge guys, I think I may have found a copy of the LRFD AASHTO that I can borrow from my previous employer, but I am still a little confused about how much the latest LRFD AASHTO has changed.

a)In building design you can design steel using ASD or LRFD, are you saying that in bridge design you can only use LRFD, not an ASD option anymore?

b)To prepare for the exam, can I use older bridge references (Tonias &amp; SERM3) to review the theory/procedures of bridge engineering along with the new LRFD AASHTO, or will that confuse me. I understand the basics of the older AASHTO. I am just not sure how much it has changed with respect to bridge engineering. Is there something I can download that goes over the changes, like revisions to the IBC.

c)IlliniASU - thanks for the attachments. I am familiar with the older ASD/LFD table and understand the change in load combinations and load factors.


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## MonteBiker (Jan 13, 2009)

ARLORD said:


> OK bridge guys, I think I may have found a copy of the LRFD AASHTO that I can borrow from my previous employer, but I am still a little confused about how much the latest LRFD AASHTO has changed.
> a)In building design you can design steel using ASD or LRFD, are you saying that in bridge design you can only use LRFD, not an ASD option anymore?
> 
> b)To prepare for the exam, can I use older bridge references (Tonias &amp; SERM3) to review the theory/procedures of bridge engineering along with the new LRFD AASHTO, or will that confuse me. I understand the basics of the older AASHTO. I am just not sure how much it has changed with respect to bridge engineering. Is there something I can download that goes over the changes, like revisions to the IBC.
> ...



a) There is no ASD Bridge design method any more on the exam. There are still some states and local agencies that will allow Standard Spec for design (in real life).

B) For the theory (chapter 4 of LRFD) most of the theory is the same but I believe that some of the coefficients for a few of the procedures have changed. You could study with your old books and work out of the new one for that but that is not something that I would depend on. For the most part, your bridge questions should be pretty basic, but I highly recommend not depending on out of date references, especially when they talk about design procedures. Just as in the switch from ASD to LRFD in steel design, they changed the equations and you will get different results. And it is likely that the differences could be large enough to get you the wrong answer.

c) Just as a FYI, AASHTO is pretty sensitive about scanning in, sharing and distributing sections of the code as it is a copyright infringement. I would not be so anxious to distribute material. I know that they just want your money and will end up changing codes more quickly than most can afford but the penalties are pretty high.

Sorry to beat a dead horse on the subject of having the right references, and being familiar with them, on the exam but they really does help.


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## MonteBiker (Jan 13, 2009)

I predict ramicoce will be the next to respond (at least within the net 5 min)


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## ramicoce (Jan 13, 2009)

ARLORD said:


> OK bridge guys, I think I may have found a copy of the LRFD AASHTO that I can borrow from my previous employer, but I am still a little confused about how much the latest LRFD AASHTO has changed.
> a)In building design you can design steel using ASD or LRFD, are you saying that in bridge design you can only use LRFD, not an ASD option anymore?
> 
> b)To prepare for the exam, can I use older bridge references (Tonias &amp; SERM3) to review the theory/procedures of bridge engineering along with the new LRFD AASHTO, or will that confuse me. I understand the basics of the older AASHTO. I am just not sure how much it has changed with respect to bridge engineering. Is there something I can download that goes over the changes, like revisions to the IBC.
> ...


Great... I think you'll be glad you've got the correct code, especially when you're thrown those basic code look-up questions. Here are responses to your comments:

a. Essentially, the client gets to choose which code is used as the basis for the design of their bridge; however, most municipalities (if not all) are switching to LRFD.

b. Sure, the fundamentals of structural analysis hasn't changed; moment distribution and influence lines work the same as they always have. However, the load factors, various coefficients, and methods are very different between the two codes. For instance, you'll be glad you had the correct code if asked about the impact factor or details of the design truck.

c. Good... the factors and combinations aren't any great leap from anything you've done; it's how you come up with the loads and resistances to be factored.

Good luck!


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## ARLORD (Jan 13, 2009)

OK, thanks, that clears it up...........

With my borrowed LRFD AASHTO, I'll be ready to put a Smack-Down on any bridge questions that appear the exam.


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## IlliniASU (Jan 13, 2009)

Darn! I missed out on all the fun.

Hmmm... copyright infringement you say... good point!

I think the most frustrating thing is studying from the 3rd edition for the exam and using the 4th edition for work. Not that they're that different... but some of the page numbers are.

Good luck on the exam!

10940623:


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