Elliptical concrete column
Elliptical concrete column
(OP)
Hi
I'm designing some bridge piers (to Eurocodes) which are to be elliptical in section and am having difficulty finding a reference or design guide as to the best way to assess them. Has anyone undertaken a design of this nature before and would have any suggestions? The piers are subject to bending and axial loading.
(I have already attempted to design them as circular columns inside an elliptical section but they are insufficient to withstand my loads).
Thanks
Cian
I'm designing some bridge piers (to Eurocodes) which are to be elliptical in section and am having difficulty finding a reference or design guide as to the best way to assess them. Has anyone undertaken a design of this nature before and would have any suggestions? The piers are subject to bending and axial loading.
(I have already attempted to design them as circular columns inside an elliptical section but they are insufficient to withstand my loads).
Thanks
Cian






RE: Elliptical concrete column
I would first check the cross section in compression...
can you give us some basic numbers? i should have something in the Office, i will post it, if i will find it
RE: Elliptical concrete column
Thanks
RE: Elliptical concrete column
Dik
RE: Elliptical concrete column
RE: Elliptical concrete column
See if it works for something 'lesser' for which there may be interaction diagrams... hadn't considered the extra point for pure tension... but, have included it in past. I was just looking into interaction diagrams a couple of days back to unravel a conc wall interaction program I wrote in Delphi about 20 years back.
Dik
RE: Elliptical concrete column
Here's a link to their website: spColumn
I quickly free-handed a rough shape - you could probably do way better than this for sure. It also works in non-English units:
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RE: Elliptical concrete column
Jae - I'm currently waiting to get SP installed on my machine at work so once I do I'll be able to make a comparison hopefully.
RE: Elliptical concrete column
There are some good suggestions above.
What kind of system is it, i haven't seen some many bridges with columns fixed on both sides?
RE: Elliptical concrete column
Ideally you'll be able to find an appropriate program to do the calculation and/or some literature to back it up. But don't forget there's a first-principles way to handle it too.
EDIT: note also, this is the way programs like spColumn, S-Concrete, etc., are doing the calculation too - some of them will actually output the strip-by-strip calculations.
RE: Elliptical concrete column
It is an integral 2-span concrete bridge. The piers will be in-situ pours fully fixed to the pier table and pile cap. I could model a pin connection at the base but as of yet I don't have SI information. Either way I need to design the pier for some amount of bending. once I get a spreadsheet set up for this it will be easy to go back and re-design if necessary.
Chad that was my first approach, I've not done much integration in a long time and it was quickly expanding to integration involving two variables so I decided to see if there was an alternative, even if it is more conservative.
RE: Elliptical concrete column
RE: Elliptical concrete column
just like JAE's sketch...
Dik
RE: Elliptical concrete column
http://blue5soft.com/en/home/
It's free for three months and then you can pay almost whatever you want.
Disclaimer: I'm not associated in any way with the software provider but I've been using it and I'd like to help the developer.
RE: Elliptical concrete column
Dik
RE: Elliptical concrete column
Best of luck - I hope you're able to find a solution that isn't too onerous!
RE: Elliptical concrete column
RE: Elliptical concrete column
RE: Elliptical concrete column
Thanks avscorreia, I got SBeton installed and ran a similar assessment, it confirms that the section capacity is sufficient, corroborating my spreadsheet. I've allowed for some bending about the Z axis which has bumped up my steel quantity. On a side note, when you first ran/installed SBeton was it giving you "an unexpected network error" warning? It will not allow me import from dxf or save the file. Apparently I need to dive into the .cfg file and alter the JIT settings. Just wondering if it's a global issue or just something on my machine.
Thanks for all the input again.
RE: Elliptical concrete column
RE: Elliptical concrete column
RE: Elliptical concrete column
Regarding the network error, I didn't notice it. I did have some problems importing the DXF file but I think it was related to the version in which it was saved.
RE: Elliptical concrete column
Output looks pretty good... program easy to use? French?
My second
firsttext for pre-stressed concrete was Beton Precontraint by Guyon, way back when...Dik
RE: Elliptical concrete column
I'm sorry if it looks as if I'm pushing this around but I guarantee that I'm not related at all with the developer. I just think that we can't get any better than this for only 20€ (or more, if we can).
Back when, we also relied on a lot of french language books, especially the ones from the EPFL for steel and concrete structures. Still use them for reference.
RE: Elliptical concrete column
RE: Elliptical concrete column