Analysis of Steel Pipe Filled with Concrete 2

[Structures33]

Hey all - Need to know how to analyze a steel pipe filled with concrete. I've searched the internet and found a couple of papers so have the allowable compressive strength now but still need allowable bending strength. Wondering if anyone has a good source. Don't have time to purchase a book.
thanks

 

[cessna98j]

It is my understanding that flexural strength of the composite section is not increased much by the addition of concrete, at least not as much as axial capacity. However, your stiffness is increased so deflections can be smaller. I've used concrete filled pipe piles a few times on marine structures for the purpose of decreasing deflections. Your additional stiffness can be quantified by EI(effective), equation (I2-14) of AISC 13th (pg. 16.1-82)

 

[cessna98j]

A further comment on the above: since there are no shear studs to get truly composite action between the concrete and the inside wall of the pipe, I don't know that any additional flexural capacity would be quantifiable. However, if you're providing a rebar cage inside the concrete then you can account for additional flexural capacity of the concrete section.

 

[Splitrings]

The AISC LRFD 3rd edition lists the moment capacity of HSS and Steel Pipe sections. It is in table 4-12 (design of compression members), down on the very bottom of the page. Theta Mn is listed for both x and y axis.

 

[Structures33]

Thanks. I was able to find a calculation to determine the composite flexural capacity.

 

[apsix]

Structures33

Now that you've started on this topic; can you share the answer?

 

[Structures33]

I found this document that provides the equations I needed. Hope it helps anyone else who may need it.

http://www.ctsee.org.tw/出版品/200310/ee0401-05.pdf

 

[rowingengineer]

Apsix, structures33(if your Aussie) you may also want to get your hands on:

"Design of concrete-filled steel tubular members according to the Australian Standard AS 5100"

I fairly sure they conclude that you can use AS5100 to design concrete filled steel tubular members.

Arguing with an engineer is like wrestling with a pig in mud. After a while you realize that they like it

 

[apsix]

Thanks Structures33, and RE

 

[racookpe1978]

I'm glad you got these (well-thought-out) answers here from structrual engineers.


(Robt is wondering how the piping and fluid flow mechanical engineers would have tried answering it ...) 8<)

 

[hokie66]

Good point, just shows the importance of posting a question in the correct forum.

 

[abusementpark]

Structures33,

Does your reference make any argument for composite action?

 

[SkiisAndBikes]

Canadian standard CAN/CSA S16-1 Limit States Design of Steel Structures, clause 18.2 contains numerous constraints and equations for concrete-filled HSS including Compressive and Bending resistance and axial compresssion combined with bending.

 

[Ussuri]

There is also a publication in the UK which provides tabulated capacities for concrete filled hollow sections. Off the top of my head I cant remember the publisher though.