Integral Abutment vrs. Span(s) Length

[asdf]

I am sure there are quite a few factors which contribute to the descision to use or not use an Integral Abutment. But I would like to know the longest contributing span length which would still allow the use of an integral abutment. I am aware that many owners have there own criteria, such as 2/3 the overall length, etc., but a general rule would be helpful.

Somewhat seperately, I would like to know your opinions of utilizing an integral abutment for a composite structure composed of 3 spans, 350' - 875' - 460', with an expansion device on the 350' end, and an integral abutment on the 460' end, and fixed bearing at both piers.

 

[Qshake]

I am not sure of the longest span used with integral abutments, but I am sure that Tennessee DOT here in the US has pioneered the use of integral abutments with long bridges. They have used integral abutments with bridges whose total length is about 600'.

There have been a few papers written about this subject. If I can dig through my files and find one or two I will post here again. Otherwise, I suggest that you check out the following websites:

http://www.asce.org

to check out the Journal of Structural Engineering or Journal of Bridge Engineering.

http://www.fhwa.gov

to check out the publications list for NCHRP.

 

[Inzynier]

Based on my recent conversation with FHWA steel bridge engineer Vasant Mistry (tel: 202-366-4599), there are no set limits for max. span lengths for bridges with integral abutments. Vasant Mistry is an author of a paper available from

http://www.nabro.unl.edu/articles/20002012/download/Vasant.pdf.

In addition there is an excellent publication by Wasserman and Walker of Tennesse DOT available from

http://www.steel.org/infrastructure/bridges/integralabutm.pdf.

It is also intersting to know that AASHTO Sec. 7.3.5. makes reference to FHWA Technical Advisory T5140.13 (1980)for guidelines regarding max. span lengths, etc. That advisory is no longer in effect, and that reference should be disregarded.