Questions_from_a_New_Civil_Guy

[Stewie_]

For a project I got a chance to read the bridge design codes, both ASD/LFD (AASHTO Standard Specifications for Highway Bridges) and LRFD (AASHTO LRFD Bridge Design Specifications) codes. While my reading I got some problems as follows,

1. The codes mention the loads and load-combinations but do not mention the exact calculation equations of effects of loads, like internal moments, shears and deflections. Where are the equations for different types of structures? Are these equations showing up in some other codes or handbooks?
The codes also say I should use elastic analysis for effects of the loads. I am really curious where I can find the detail explanation of elastic analysis. Is that from textbooks or some other specifications?

2. Correspondingly, the codes mention the nominal strength of materials but do not give the calculation equations for strength of members, like the flexural strength of the beam. Where can I find these equations?

Thank you, guys. Really hope get some hints or answers.

 

[JedClampett]

You need to go walk into the office next to yours and ask the not so new Civil guy these questions. There's no harm in having this stuff explained to you face to face.
A code is not a textbook. It prescribes design allowables and acceptable materials, not analysis procedures (usually).

 

[Ron]

dapinmin...most of what you are looking for is in any civil/structural curriculum in college. What type of engineering degree do you hold?

Agree with JC...any of the guys who can and should be mentoring you could answer those questions. Don't hesitate to ask.

 

[csd72]

Agree with above, these are things that you really should know. did you sleep through your structural mechanics classes?

It is fundamentals like these that are the reason why we are expected to have a degree.

Sorry to be so blunt but these are really fundamental concepts.

 

[MiketheEngineer]

Ditto

Codes dictate MINIMUM loads - your training should tell you how to handle them.

 

[DWHA]

1. The codes mention the loads and load-combinations but do not mention the exact calculation equations of effects of loads, like internal moments, shears and deflections. Where are the equations for different types of structures? Are these equations showing up in some other codes or handbooks?

This is basic Statics

2. Correspondingly, the codes mention the nominal strength of materials but do not give the calculation equations for strength of members, like the flexural strength of the beam. Where can I find these equations?

You have to look in the section of the manual corresponding to the materials. There are equations for flexural strenght of beams (both steel and concrete) in their respective sections.

But as stated by others, you must have an understanding of structrual mechanics to be able to perform this work.

 

[chicopee]

"For a project..." sounds like school work, if it is not, oh boy we are all in trouble.

 

[JedClampett]

I'm giving him the benefit of the doubt. He (she) didn't say he was designing to the code, just that he read the code and wanted to know how we got to the part where the stresses/moments/etc. were calculated. Maybe he's curious. Maybe he's strictly a Civil/Water Treatment/Road/Curb and Gutter guy and didn't get much coursework on structural stuff.