Analysis of Riveted Structure
Analysis of Riveted Structure
(OP)
I have a RFP for a project that involves built-up, riveted structural roof members. The idea (good or bad) is to add rooftop equipment to this portion of the roof. I have no idea where to start with budgeting for this type of analysis. No drawings/specs exist for the existing structure so intense field verification will be required. It is a square, symmetric building so I have that going for me. Can anyone share their thoughts on how to budget my time for a riveted structure like this? I will also take any advice on papers, books, etc. that will help me with the actual analysis of the structure.






RE: Analysis of Riveted Structure
This Link document entitled "Rivets In Bridge Construction" from SlideRuleEra's website may be of assistance for analysis etc.
Click on the title about 2/3rds down the page that takes you to a ZIP file download.
RE: Analysis of Riveted Structure
The fee question is a little trickier. With saliva covered thumb in the air...
1) 16 hrs extra for two all day site visits.
2) 12 hrs extra for learning about rivets and developing some tools where needed.
3) $3500 for some materials testing by a sub (or acknowledge as an extra to the contract).
4) 20% contingency on everything related to the riveted members to give you some wiggle room.
I like these kinds of projects as T&E not to exceed. That's not always palatable to the client of course.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Analysis of Riveted Structure
About 114 years more current that my reference
RE: Analysis of Riveted Structure
Historical Allowable Stresses For Rivets
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RE: Analysis of Riveted Structure
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Analysis of Riveted Structure
I did an upgrade to an old industrial building once with crane rails going from 5 ton bridges to 20 ton...some with rivets.
I learned two things:
1. A bad rivet can be "found" by hitting the head of the rivet with a ball peen hammer - if it rings its good - if it thuds, you've got a bad rivet.
2. Watch out for old steel with paint on it if you need to weld. We had a couple of welders get a bit sick from fumes off the lead based paint.
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RE: Analysis of Riveted Structure
I recall hearing the advice from a former welding superintendent that riveted materials were not necessarily weldable- some of the stuff would pop and all when you started welding on it, less chemical control than in later years. (He was referring specifically to plate materials.) The Titanic with high-sulfur plate comes to mind.
RE: Analysis of Riveted Structure
On a recent project that was to repair a bridge crane using rivetted construction, coupons taken of the original material showed a high sulphur content... and the material was 'hot short' and welding was out of the question.
Dik
RE: Analysis of Riveted Structure
RE: Analysis of Riveted Structure
I can also vouch for the difficulty of welding material from that era -- all of our retrofits replace rivets with HS bolts. Lead paint is definitely a big hazard, we often have craft in full suits for the actual work, and everyone observing using respirators.
KootK, where welding is possible metalurgically, I'd back the idea of load sharing. If J1.9 allows sharing between rivets and SC bolts, I think rivets and welds would work similarly.
And just to round out being too late to the party -- Jstephen is right, analysis methods of the time don't always line up with our methods and codes today. Usually it's conservative, but especially on the local level there are sometimes conundrums. Sometimes you just have to use the "it's worked for 80 years" argument to pass the AHJ's review.
RE: Analysis of Riveted Structure
RE: Analysis of Riveted Structure