Concrete Portal frame 2

[civeng80]

Has anyone ever designed a concrete portal frame?
If so how did you go about designing the column to rafter transitions/connections?
Is there any literature on this at all?

Thanks all!

 

[csd72]

Yes but not in a seismic zone, is this a seismic zone?

There is plenty of literature on concrete detailing, I suggest you google it.

 

[csd72]

When all elso fails:

http://www.erico.com/products.asp?folderid=173

 

[civeng80]

Not in a seismic zone.

 

[civeng80]

Im interested in the connection details of beam to column with a construction joint at the column and the rbar layout.

Precast concrete construction and/or insitu.

Anyone can help me ?

 

[gyroman10]

use "Structural Details in Concrete" book by M.Y.H. bagash very good reference for detailing.

 

[csd72]

check out the pci website:

http://www.pci.org/resources/home_eng.cfm

 

[civeng80]

Thanks Gyroman

But I couldn'y find any reference to that book in Amazon. Is it an old book or something like that?

 

[civeng80]

Actually theres a site that you can download it from. But I cant do it ! Can it be downloaded?

Thanks

Looks like a good book!

 

[gyroman10]

civeng80

here i scaned the page of portal frame detailing for you. this illustrates all.

 

[hokie66]

I suggest you get proficient in the strut and tie method of design, as it is applicable to the knee region of a portal frame. For a start, check out threads on this site, including one currently active on the "Structural Engineering Other Topics" forum.

 

[csd72]

http://www.gostructural.com/pg.asp?id=20

 

[civeng80]

Thanks!

I will look into Strut and Tie method. Hokkie66 is this method used frequently here in Australia? Are concrete portal frames used much here also?

Gyroman10 where is it possible to get Bagash "Structural Details in Concrete" from?

 

[hokie66]

The strut and tie method is used in Australia. In my experience, it is mostly used for pile caps, corbels, setdowns in beams and slabs, and any member where the ratio of length to depth is say 4:1 or less. Your Warner, Rangan, et al book has a good primer, and the paper which csd72 referenced is good also.

Concrete portal frames are rare here, I believe. It would be interesting to know your application.

 

[civeng80]

Thanks Hokie66

I see Warner, Rangan at el has a whole chapter on the method.

I'll look into it. Obviously the method hasn't been around all that long right?

 

[civeng80]

Hokie66!

Been asked by a precast concrete firm the merits of using concrete portals. I agree concrete portals not used much here.

 

[hokie66]

Not sure how long it has been around, but the Warner Rangan et al "bible" didn't include it in the 1989 edition, but did in the 1998 one.

There are lots of pitfalls in designing for the forces around a knee in concrete. I try to avoid this type structure, and am very conservative if forced into using one. As well as the strut and tie information, read the Chapter in Warner "Guidelines for Detailing". Makes you very wary of this type connection.

 

[gyroman10]

i did a concrete portal frame once, and had to subcontract a part of job to a Phd engineer who modeled the joints using ANSYS, he did the finite element analysis on the joint. The portal frame was 78' feet span.

civeng80 i am sorry i dint find the book on any internet book store, i bought this book from amazon.com 7 years ago.

 

[civeng80]

Thanks gyroman10

Very interesting your span is about what Im looking at at the moment. I note that the portal is in two parts and pinned at the ridge point. Just wonder how its erected and the roofing material and walling was it all concrete or metal?

What sort of dimensions did he come up with for beam and columns??

Cheers!

 

[csd72]

One more reference:

http://ocw.mit.edu/NR/rdonlyres/Civ...4457-9F61-D56EBB993AD2/0/o_09_bm_clmn_jnt.pdf